To observe the clinical curative effect of Didang decoction on diabetic patient with lower extremity arterial vascular lesions of phlegm and blood stasis binding syndrome, and at the same time analyze the influence on the hematology indexes like CD40/CD40L and IL-10. Methods:A total of 70 cases of diabetic patient with lower extremity arterial vascular lesions of phlegm and blood stasis binding syndrome who treated in the endocrine department in Taihe Hospital from April 2016 to April 2017 were included in the study and randomly divided into the control group and the observation group, with 35 cases in each group. The control group adjusted dietary pattern, strengthened exercise and daily injections of human insulin. Besides, the treatment group was added Didang decoction on the basis of the control group. TCM syndrome integrals, insulin as well as FPG levels, CD40, CD40-L and IL-10 changes in serum concentration levels of two groups before and after treatment were compared. Results:1)TCM syndrome integrals of the two groups reduced than before the treatment (P<0.05), the reduction of the treatment group was more significantly than the control group (P<0.05). 2)the levels of insulin as well as FPG declined after treatment (P<0.05), and the downward trend of the test group was more obvious. Compared with the control group, there were with statistically significant differences (P<0.05). 3)Detected by ELISA, CD40 and CD40L levels of the two groups of the patient decreased after treatment, while IL-10 levels of both group were higher after treatment with significant differences (P<0.05). Apart from this, the upward trend of the treatment group was higher than the control group. Conclusion:The modified Didang decoction can effectively treat diabetic patient with lower extremity arterial vascular lesions of phlegm and blood stasis binding syndrome, and the mechanism may related to the reduction of CD40/CD40L expression and increase of IL-10 level.