Recently, we found some cases of irregular decitabine treatment resulting in serious complications, difficulty in determining the efficacy and loss of confidence in the treatment: the following explanations are given: 1) Not all MDS patients are suitable for decitabine treatment; it is generally recommended for patients with RAEB1 or higher, or RCMD with a tendency to progress to high risk (patients with chromosome 7 or complex abnormalities); or RCMD combined with refractory Patients with platelet leukopenia; patients with transplantation indications can also use decitabine to avoid disease progression until a suitable donor is found; 2, decitabine is still fully self-funded, but if the patient belongs to the medical insurance category, other costs during hospitalization can be reimbursed; 3, the response rate of decitabine 4 courses of treatment is 50 – 60%; complete remission is about 30%; patients with response still have relapse after long-term discontinuation Because decitabine is a demethylation therapy, it works by restoring the activity of oncogenes in the patient’s body, and there is a long period of myelosuppression before the clonal cells are inhibited and the normal cells grow normally, and the platelet white blood cells are low, so the first and second courses of treatment are prone to bleeding and infection, and the efficacy may not be seen yet; 5. These hospitals will review the bone puncture before the third course of treatment to determine whether it is necessary to continue the drug; 6. In conclusion, we hope that decitabine, which is widely used internationally and significantly prolongs the survival of high-risk MDS patients who cannot be transplanted or who do not choose to be transplanted, can be properly and rationally applied in China, giving MDS patients more treatment options.