Objective To study the efficiency of the first time platelet transfusion in patients with blood diseases.Methods Investigate the effect of platelet transfusion in 87 patients with blood diseases.All the patients were transfused 10U platelet (platelet≥2.5×1011 ).Observe CCI after platelet transfusion and analyse the influence factors to the efficiency of the first time platelet transfusion such as the kind of diseases,splenomegaly,fever,age and sex.Results After platelet transfusion,66 patients (75.9 ％) were effective.The efficancy rates were 80.0 ％,78.1％,65.2 ％,82.3 ％ in AA,ITP,AL,MDS (x2=2.88,P＞0.05).In 31 patients with a fever and infaction the efficancy rate was 58.1％,but it was 85.7％ in 56 patients without a fever and infaction (x2=8.3308,P＜0.01).The efficancy rate in 59 patients with non-splenomegaly was 86.4 ％.It was higher than that in 28 patients with splenomegaly which was 53.6％(x2=11.2033,P＜0.01).The efficancy rate was 76.0％ in male patients and it was 75.7 ％ in female patients (x2=- 0.0012,P＞0.05).The efficancy rate was 74.5 ％ in young group (＜60 years old)and 77.8 ％ in old group (≥60 years old)(x2=0.1231,P＞0.05).Conclusion Fever and splenomegaly are the influence factors to the efficiency of the first time platelet transfusion.