Objective To observe the 12-lead ECG (electrocardiogram) characteristics of Japanese rabbits, and provide basic ECG data for cardiovascular disease research. Methods The 12-lead ECG and X-rays of 55 male Japanese rabbits were recorded in supine position after intraperitoneal injection of 20% urethane. Results ECG:① The 12-lead ECG characteristics of male Japanese rabbits were similar to humans. The rabbit heart rate was 265.5±36.8 beats/min, faster than that of humans. No arrhythmia was found in all the 55 rabbits. ② The supine position average ECG axis was between 19° to 250°, varying a lot. ③ P wave:The shape of P wave was blunt round or a little bit sharp. P waves were all in accordance with the sinus P wave rules, which were more obvious in lead II, aVF and all chest leads. ④ The PR interval was 0.063±0.007 s. ⑤ The QRS duration was 0.040±0.005 s. The main waves were mostly upward in leads Ⅱ, Ⅲ, and aVF. The same as humans, the R/S ratios were increased by degrees in chest leads. ⑥ The ST segment was short, and was located in the equipotential line. ⑦ The shapes of T wave were mostly round, partly had twin peaks. T waves were more obvious in leads Ⅱ, Ⅲ, aVR, and AVF and chest leads. ⑧ The QT interval was 0.142±0.015 s, and QTc was 0.306±0.034 s. In the X-rays, most heart shadows were in the center and right chest. Conclusions The normal values of 12-lead ECG characteristics of Japanese rabbits are obtained in this study, which are of certain application value in experimental studies of cardiovascular diseases.