Objective To observe the effect of Tongdaosan on blood platelet index as well as nail fold microcirculation in patients with blood stasis syndrome of psoriasis.Methods Total of 60 patients with blood stasis syndrome of psoriasis were randomly divided into 2 groups,the treatment group was treated with Tongdaosan and the control group was treated with Xiaoyinpian.Results Compared with the control group,blood platelet index as well as nail fold microcirculation of the treatment group were significantly different(P