Purpose:To study the distribution of blood pressure in the cardiovascular system of rat. Method:The experimental animal is Wistar rat (n=lS). The blood pressure in different parts of the cardiovascular system were recorded with a 4-channel polygraph system under closing condition. This method is more exact than that of manometer. Results:Our experiments demonstrated the following distribution of blood pressure in the cardiovascular system of rat. (1) The left ventricular systolic pressure(LVSP ) was 145.00+15.16 mmHg and the aortal systolic pressure(ASP ) was 126.87+11.16 mmHg. The LVSP was higher than ASP. The right ventricular systolic pressure(RVSP ) was 35.04+3.95 mrnHg and the pulmonary arterial systolic pressure(PASP) was 27.0313.46 mmHg. The RVSP was higher than PASP. This distribution of blood pressure was different with human. (2) On Value and range, the blood pressure in vascular system of rat (including A SP、A DP、MA P、PA SP、PA DP、MPA P、CVP、 WP)were clese to human. Conclusion: (1) The LVSPwas higher than ASP and the RVSP was higher than PASP. This distribution of blood pressure of rat was different with human. (2) The LVSP and RVSP of rat were higher when compared with human and the blood pressure distribution of other parts in the vascular system of rat was close to human