Objective:To observe the curative effects and the influences of Yueanxin injection (YAXI, 悦安欣注射液) on acute cerebral infarction (ACI) and on blood rheology separately. Methods:Sixtytwo cases with ACI were randomly divided into treated group ( n=31) which was treated with YAXI and control group (n=31) which treated with tetrameth ylp yrazine injection (川芎嗪注射液) as control. Once a day for 30 days as a therape utic course to both groups.The curative effects and the changes in blood rheology parameter s were observed.Results:The marked effective rate (74.2%) and total effective rate (96.8%) in treated g roup were significantly superior to those (38.7% and 67.7% respectively) in cont rol group (P<0.05 or P<0.01). The improvements of blood rheology param eters in tr eated group were significantly better than those in control group (P<0.0 5 or P<0.01).Conclusions:The curative effects of YAXI on ACI are sufficient.