Abstract: OBJECTIVE To investigate into the effect of Radix Salviae Miltiorrhizae drug serum on blood vessel endotheliocyte secretions ET,SOD and MDA and the its mechanism in the treatment of blood stasis.METHOD LPS and Radix Salviae Miltiorrhizae drug serum were made to act on human umbilicus venous endotheliocyte,and the clear supernatant was taken for the determination of the levels of ET,NO,SOD and MDS.RESULT Radix Salviae Miltiorrhizae drug serum could relieve the rise of NO and ET caused by LPS and the decrease of SOD and increase of MDA caused also by LPS.CONCLUSION Radix Salviae Miltiorrhizae can maintain NO and ET dynamic equilibrium,remove free radicals and maintain the normal physiological functions of the blood vessels,thus effectively prevent blood stasis.