Objective To study the effect of Xi Yanping injection on electrocardiogram in Beagle dogs. Methods 24 Beagle dogs were divided into negative control group (0 mg/kg), low-dose group (15 mg/kg), middle-dose group (75 mg/kg), high-dose group (250 mg/kg).Each group consist of 3 animals/sex/group, all animals were administrated by intravenous drip at 20 mL/kg once a day. Administration period was 28-days with 14-days recovery phase. Animals LeadⅡ electrocardiogram (ECG) was measured during quanrantine, administration and recovery phase. The following parameters included heart rate, P -R interval,Q - T interval, P, Q, R S wave amplitude and ST and T wave amplitude were determined, serum biochemical parameters were measured to evaluate the effect on main organs. Results All parameters of quarantine period were fell in the normal limit. After the first administration, heart rate decrease was found in low dose group and P-R interval prolongation was found in high dose group. No abnormal was found in dose metaphase,end of dose stage and recovery stage. Conclusion Xi Yanping injection had no obvious influence on ECG of Beagle dog.