Chemotherapy (chemotherapy), the treatment of disease with chemically synthesized drugs. These particular drugs kill tumor cells and are sometimes called cytotoxic drugs. Some chemotherapy drugs are derived from extracts of plants in nature, and some are synthesized by man. There are nearly 100 types of chemotherapeutic drugs commonly used in clinical practice, including: adriamycin, erythromycin, mitomycin, and fluorouracil deoxynivalenol. These drugs are often applied in combination in different strengths. Chemotherapy is currently the main treatment for tumors and certain autoimmune diseases, but in addition to the obvious side effects such as nausea and vomiting, hair loss or bone marrow suppression commonly experienced by patients, in recent years, the medical community has also noticed that chemotherapy may fail to kill tumor cells due to the emergence of multidrug resistance in tumor cells, resulting in reduced or ineffective chemotherapeutic efficacy. Chemotherapeutic drugs such as natural large-molecule lipid-soluble drugs, such as anthracyclines (adriamycin), vincristine, onychomycetes, and paclitaxel, are prone to induce the development of tumor multidrug resistance. Multidrug resistance in tumors refers to the cross-resistance of tumor cells to multiple antitumor drugs of natural origin with different structures and mechanisms of action at the same time after being exposed to one antitumor drug and developing resistance to it. Multidrug resistance is a common way of drug resistance in tumor cells and a major reason for the failure of tumor chemotherapy. There are two main types of multidrug resistance: (1) intrinsic multidrug resistance: It refers to the inherent insensitivity of tumor cells to chemotherapeutic drugs, for example, hepatocellular liver cancer is an inherently drug-resistant tumor cell, which is generally insensitive to chemotherapeutic drugs, so systemic chemotherapy is rarely used in the treatment of liver cancer; (2) acquired multidrug resistance: It refers to the tumor being sensitive to chemotherapeutic drugs at the beginning, but after several courses of chemotherapy, the tumor cells not only become sensitive to the drug, but also become resistant to it. (2) Acquired multidrug resistance: It means that tumors are sensitive to chemotherapeutic drugs at the beginning, but after several courses of chemotherapy, tumor cells become resistant not only to the drug, but also to drugs with different structures and mechanisms of action. When tumor cells are exposed to anti-cancer drugs for a long time, multi-drug resistance genes are induced to be amplified and expressed in large quantities, which rapidly pump out the toxic chemotherapeutic drugs entering tumor cells and reduce the intracellular accumulation of drugs and the cytotoxic effect of drugs, thus playing a protective role for tumor cells. This reduces the intracellular drug accumulation and weakens the cytotoxic effect of the drugs, thus playing a protective role against tumor cells, making chemotherapeutic drugs become powerless against tumor cells. The mechanism of tumor multi-drug resistance is quite complex and is a multifactorial process. Therefore, it is important to find a low-toxic, highly effective and economical drug to reverse tumor multi-drug resistance to overcome tumors. Since Beidler first discovered the phenomenon of tumor cross-resistance in 1970, reversing tumor multi-drug resistance has become one of the hot spots of research. Currently, the multidrug resistance reversal agents developed in western medicine include calcium channel blockers (isobodine and its derivatives), calmodulin antagonists (phenothiazines), immunomodulators (cyclosporine A and its derivatives), steroid hormones (megestrol, progesterone), estrogen antagonists (tamoxifen, toremifene), antimalarials and antiarrhythmic drugs (quinine, quinidine), non-cytotoxic insulin analogs and vincristine analogs. and vincristine analogues, etc., but most of them have certain toxic side effects. The representative drugs of the first generation of reversal agents are isobodine and cyclosporine A. The concentration of isobodine required for effective reversal of multidrug resistance in vitro is often high, and strong cardiovascular toxicity occurs in humans, while the immunosuppressive effect of cyclosporine A greatly limits its clinical application. Second-generation reversal agents such as VX710, PSC833 and XR9051 are 3 to 100 times stronger than first-generation reversal agents. Their common toxicities are ataxia and hyperbilirubinemia, and these reversal agents, like first-generation reversal agents, can significantly alter the hemodynamics of anticancer drugs, resulting in significantly lower blood concentrations reaching tumor cells, thus affecting the antitumor efficacy of chemotherapeutic drugs. In long-term clinical practice, it has been noticed that the combined application of radiotherapy and TCM can improve clinical efficacy, improve patients’ quality of life and prolong survival, which is superior to Western medicine treatment alone. At first, it was generally believed that the mechanism was that TCM could regulate and improve the immune function of the body, but later it was gradually noticed that TCM had obvious advantages of potentiation and toxicity reduction, which could prevent or reverse the multi-drug resistance of tumors. Takara et al. found that rhubarb, scutellaria, scutellaria, poria, jujube, dried ginger, licorice, and ephedra significantly reversed the resistance of tumor cells to paclitaxel without affecting the sensitivity of tumor cells to 5-fluorouracil, among which rhubarb, poria, and ephedra acted partly by affecting the expression of multidrug resistance genes in tumor cells to reverse drug resistance. Other drugs such as ginseng, Chuanxiong, turmeric, tannin, antifungal, zhebei, rhubarb, scutellaria, scutellaria, Andrographis paniculata, and toad skin have been experimentally confirmed to have reversal of multidrug resistance. It is worth noting that the traditional Chinese beverage with the characteristics of medicine and food: green tea, which is both food and traditional medicine to clear heat and cool the liver. Chinese medicine believes that tea can change the “medicinal properties”, (from the modern medical point of view is likely partly because it affects the metabolic process of drugs in the body), therefore, unless the prescription contains green tea, patients are usually asked not to drink tea at the same time during the medication. However, recent studies have shown that theophyllin, theanine, epicatechin, and flavonoids contained in green tea can significantly reverse the resistance of various tumor cells to adriamycin, the mechanism of action of which is not yet clear. Compared with chemical drugs for reversing tumor multidrug resistance, Chinese medicine has certain superiority, which is reflected in: 1. Because of the non-unitary nature of Chinese medicine components, its effect of reversing multidrug resistance is often not limited to a single target, but through the comprehensive effect of multiple targets; 2. Some Chinese medicines have anti-cancer effects by themselves; 4. Chinese medicines can improve the immune function of the body, while having multiple effects such as inhibiting tumor cell proliferation and angiogenesis, inducing tumor cell differentiation and apoptosis. Regarding the study of Chinese medicine in reversing multidrug resistance, my personal view is that: 1. The study of Chinese medicine in reversing multidrug resistance in tumors should not be limited to the use of modern medical methods to detect the apoptosis-inducing or drug-resistant effects of certain Chinese medicines or formulas on tumor cells, but more importantly, should be guided by the basic theories of Chinese medicine with Chinese medicine characteristics, and should not be detached from the overall concept of Chinese medicine and the idea of evidence-based treatment. The experimental research focuses on Chinese herbal medicines alone, but the clinical practice should also focus on the application of the combination of Chinese herbal medicines in prescriptions and the use of multiple Chinese herbal medicines in combination to better take into account the patient’s condition. Because patients suffering from tumor chemotherapy often have bone marrow suppression, immune deficiency or gastrointestinal symptoms such as nausea and vomiting due to chemotherapy side effects while suffering from tumor, the treatment should not only take care of one side, but should take into account all aspects and give comprehensive treatment with the combination of anti-tumor, reversal of drug resistance and auxiliary orthopedic drugs, which is also the problem of multi-target and multi-path treatment of tumor that we often talk about clinically. While reversing the resistance of tumor cells, the multidrug resistance reversal agents in modern western medicine system may also increase the damage of chemotherapy drugs to normal human cells, especially to chemotherapy-sensitive bone marrow hematopoietic cells, and bone proliferation inhibition is the dose-limiting toxic reaction of many chemotherapy drugs. It is not clear whether Chinese herbal medicine reverses tumor cell resistance while increasing the damage of chemotherapeutic agents on normal human cells. From the limited observation so far, Chinese medicine not only does not increase the damage of chemotherapeutic drugs to normal human cells while reversing tumor cell resistance, but also has a certain chemotherapeutic detoxification effect, i.e. some Chinese medicines have certain tumor tissue specificity for tumor treatment and reversal of drug resistance, which is an interesting phenomenon that deserves further in-depth study.