Patients treated with Chinese medicine often ask, “How long is the right time to take Chinese medicine?” Our answer is at least 2 to 5 years of taking Chinese herbal medicine treatment, depending on the condition and individual circumstances. Why do we need to take Chinese medicine for a long time? Can long-term consumption of traditional Chinese medicine effectively prevent recurrence and metastasis of lung cancer? Recurrence and metastasis are one of the characteristics of malignant tumors, and also the main reason for the failure of surgery and radiotherapy. Chinese medicine also has a profound understanding of the occurrence and metastasis of tumors. According to Chinese medicine, if the vital energy is strong, the qi and blood are full, the internal organs of human body function normally, and the body is in balance, it is not easy to get sick; if the body can be actively treated after getting sick to restore the balance, it is not easy to recurrence or metastasis. As the Su Wen says, “When the righteousness is inside, the evil cannot dry up” and “When the evil comes together, its energy must be weak”. If the body is deficient, the disease will be transmitted, which can promote the development and metastasis of tumor. It is written in “The Beginning of All Illnesses” that “the deficiency of evil in the people, …… stays and does not go, it is transmitted to the veins”, “stays in the veins and does not go, resting and becomes accumulation. Or to the Sun vein, or to the luo vein, …… or to the collection of the intestines and stomach of the original, the upper connected to the slow tendons, the evil qi kink u, can not win the argument.” It can be seen that the weakness or deficiency of the body’s positive energy is the key factor causing the occurrence, development and metastasis of tumors. On the other hand, “residual toxin not yet cleared” is the most basic and important reason for tumor metastasis. After tumor surgery and radiotherapy, although the evil Qi gradually disappears, there is still cancer toxin lying in the body. According to Chinese medicine, cancer toxin is slow in nature, fierce in toxicity, easy to spread, easy to consume vital energy, easy to cause stagnation, etc. It is easy to metastasize along meridians, veins and blood vessels. The internal accumulation of cancer toxin injures the function of internal organs and generates phlegm over time, forming phlegm-poison interlocking knots; the internal accumulation of cancer toxin blocks qi flow and stagnates blood vessels as stasis. The interconnection of phlegm and stasis, which is depressed for a long time and decayed, will coalesce into toxicity. Phlegm, toxin and stasis interact with each other, resulting in the interlocking of phlegm, stasis and toxin, which promotes the metastasis of tumor. To sum up, the deficiency of positive energy and the interlocking of evil energy are the fundamental factors that cause or promote tumor metastasis. Therefore, accordingly, the two treatment principles of “supporting positive energy and consolidating the root” and “eliminating evil and detoxifying” form two important treasures in Chinese medicine to combat tumor metastasis. There are various means to treat lung cancer in TCM, including soup, pill, powder, cream, external application of Chinese medicine, Chinese medicine bath, acupuncture, massage, qigong, etc. The combined application of multiple therapies can form a synergy to achieve the purpose of cancer prevention and treatment. In particular, Chinese medicine, based on the individualized characteristics of evidence-based treatment, can bring into play the advantages of treating tumors with tumors and preventing changes without tumors, according to the pathological mechanism of cancer patients of “positive deficiency and evil solidity”. Since the occurrence of tumor is not achieved overnight and the human body is endowed with innate constitution and influenced by long-term growth habits, it takes a relatively long time to improve the imbalance of the human body through traditional Chinese medicine. For patients with early stage and radical cure by surgery, if they can adhere to the exercise, regulate their emotions and rationalize their life and diet, they can consider stopping the medication in 2~3 years; for patients in the middle stage and patients with milder disease but with many clinical symptoms or weaker body, it is better to consider stopping the medication after 3~5 years of medication according to the clinical condition; for lung cancer patients who survive with tumor, they need to take medication for a long time. In general, long-term use of TCM and other TCM integrated rehabilitation methods after surgery and radiotherapy and chemotherapy can prevent or delay the metastasis and recurrence of tumor. However, Chinese medicine is not the only treatment method. Psychological factors, dietary factors, exercise factors, etc. may affect the recovery of the body. In order to prevent tumor recurrence and metastasis and prolong life, we should actively adopt TCM comprehensive rehabilitation therapy (integrated treatment with herbal medicine, psychological intervention, physical exercise and nutritional guidance) at the same time of taking medicine.