Abstract：Objective：To observe the curative effect and safety of Kangbai Yannian tang No.1 prescription combined with preexcitation chemotherapy on hematology and Chinese medicine symptoms of patients with high-risk myelodysplastic syndrome. Methods：A total of 38 cases of patients with high-risk myelodysplastic syndrome were randomly divided into the control group and the combination group，18 and 20 cases in each group. The control group was treated with preexcitation chemotherapy(decitabine plus CAG or HAG)， and the combination group was treated with Kangbai Yannian tang No.1 prescription combined with preexcitation chemotherapy. The changes in hematologic indexes and Chinese medicine syndrome scores in the two groups were observed，and the clinical effect was evaluated. Results：There was no significant difference being found in the comparison of peripheral hemogram before treatment between the two groups(P＞0.05). After treatment， there was no significant difference being found in the comparison of peripheral hemogram at each time point between the two groups(P＞0.05). Before treatment，no significant difference was found in the comparison of the percentage of initial cells between the two groups(P＞0.05). The comparison of the percentage of initial cells at each time point in the two groups before and after treatment showed significance in the difference(P＜0.05). The percentage of initial cells in the peripheral blood 8 and 12 weeks after treatment in the combination group was decreased when compared with that in the control group(P＜0.05)；the percentage of initial cells in the bone marrow 8 and 24 weeks after treatment in the combination group was decreased when compared with that in the control group(P＜0.05). Before treatment， there was no significant difference being found in the comparison of Chinese medicine syndrome scores between the two groups(P＞0.05). After treatment， the comparison of Chinese medicine syndrome scores at each time point between the two groups showed significance in the difference(P＜0.05). After treatment，the improvement of Chinese medicine syndromes at each time point in the combination group was better than that in the control group(P＜0.05). The Mann-Whitney U test showed that there was no significant difference being found in the comparison of the curative effect between the two groups(P＞0.05). The mortality or conversion rate was 22.22% in the control group and 20.00% in the combination group，there being no significance in the difference(P＞0.05). The survival rate without any development of diseases was 77.77% in the control group and 80.00% in the combination group， there being no significance in the difference(P＞0.05). Compared the total survival days and the survival days without any development of diseases between the two groups，there being no significance in the difference(P＞0.05). There was no significant difference being found in the comparison of the observation indexes of safety between the two groups(P＞0.05). Conclusion： The therapy of Kangbai Yannian tang No.1 prescription combined with preexcitation chemotherapy in treating patients with high- risk myelodysplastic syndrome can relieve their clinical syndrome，and downregulate the percentage of initial cells in peripheral blood and bone marrow. Further study of the cases can be carried out.