OBJECTIVE： To observe the effects of Zhuangtongyin （ZTY） water extract on blood vessels diastolic and systolic function and cardiac function in rats with coronary heart disease （CHD） and its potential mechanism. METHODS： SD rats were randomly divided into control group， sham operation group， model group， positive group （Compound danshen dripping pills， 0.08 g/kg） and ZTY water extract low-dose， medium-dose and high-dose groups （6.8， 13.6， 27.2 g/kg， by weight of water extract）， with 10 rats in each group. Except for control group （no operation） and sham operation group （only open chest without ligation）， CHD model were set up in other groups by ligating the left ventricle cyclotron endings. One week after modeling， control group， sham operation group and model group were given constant volume of water intragastrically， and administration groups were given relevant medicine intragastrically； once a day， for consecutive 4 weeks. Two hours after last administration， cardiac function indexes （LVEDV， LVESV， SV， LVEF） of rats were detected in each group. The levels of inflammatory factors （CRP， IL-1β， IFN-γ and ET-1） in myocardial tissue were determined by ELISA. Histomorphological characteristics of myocardial tissue were determined by HE staining. RESULTS： The structure of myocardial fibers in control group and sham operation group was clear and orderly； there was no statistical significance in difference of each index between 2 groups （P＞0.05）. Compared with control group， myocardial fibers were disorderly arranged in model group， and the phenomena of rupture， dissolution and necrosis were observed， accompanied by infiltration of inflammatory cells. The levels of LVEDV and LVESV as well as the levels of CRP， IL-1β， ET-1 and IFN-γ were increased significantly， while the levels of SV and LVEF were decreased significantly （P＜0.05 or P＜0.01）. Compared with model group， above symptoms of rats in each administration group were improved to different extents； the levels of LVEDV and LVESV as well as the levels of CRP， IL-1β， ET-1 and IFN-γ in positive group， the levels of LVEDV in ZTY water extract medium-dose and high-dose groups， the levels of LVESV and CRP， IL-1β， ET-1， IFN-γ in ZTY water extract groups were decreased significantly. The levels of SV and LVEF in positive group， the levels of SV in ZTY water extract groups as well as the levels of LVEF in ZTY water extract medium-dose and high-dose groups were increased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： ZTY water extract could reduce the level of ET-1 and improve blood vessels diastolic and systolic function in CHD model rats， then restore blood supply of myocardial tissue and strengthen cardiac function， by acting on inflammation cycle.