Abstract： Objective To observe the long-term toxicological effects of Suxiaokangyun capsules in Beagle dogs. Methods For long-term toxicological experiment, 24 Beagle dogs were randomly divided into 4 groups, and were given intragastrically Suxiaokangyun capsules at a dosage of 17.5 mg/kg, 35.0 mg/kg, 87.5 mg/kg for a duration of 90 days. Thirty days after termination of drug treatment, general physical status,weight, rectal temperature, ECG, hematological, biochemical and urine indices were measured and pathological examinations were also made. Results When compared with those of the control group, excitement elevated and weight of the animals decreased with increasing dosage. No statistical changes were detected in general physical status, when compared with that of the control group. And neither significant differences in ECG,hematological, biochemical and urine indices nor morphological changes probably induced by drug toxicity could be detected in the vital organs or tissues. Following termination of drug treatment, the weight and general status of the animals returned to normal, without obvious delayed drug reaction. Conclusions Animal experiments revealed that safe dosage for prolonged administration of Suxiaokangyun capsule was 17.5 mg/kg.