Objective To investigate the effect of Tangxin Heji （Compound capsules for diabetic patients with cardiac insufficiency） on the cardiac function in type 2 diabetic patients with heart failure.Methods Totally 49 type Ⅱ diabetic patients were randomized into control group of 20 cases

and treatment group of 29 cases.The conventional therapy such as cardiotonic

diuretic

angiotension-converting enzyme inhibitor

β-receptor blocker

and nitrate medications were conducted in the control group.The treatment group was administered Tangxin Heji additionally on the basis of conventional therapy

4 capsules each time

3 times a day.The treatment lasted 12 weeks.The clinical effect of the two groups was compared.Before and after treatment

the left ventricular end diastolic diameter （LVEDD）

the left ventricular end systolic diameter（LVESD）

the left ventricle ejection fraction（EF）

the left ventricle fraction shorting（FS）

and the maximum systolic blood flow velocity of early diastolic / late diastolic（E/A） were detected by echocardiography for evaluating the heart function.Results The total effective rate of the treatment group and the control group were 89.65% and 60% respectively

the former was superior to the latter（P<0.05）.The heart function indices of the treatment group were improved and there was a statistical significance in difference（P<0.05 or P<0.01）.The EF and FS of the control group were improved after treatment（P<0.01）

while the improvement in the treatment group was more than that of the control group（P<0.05 or P<0.01）.The safety indices of both groups showed no obvious changes after treatment.Conclusion Tangxin Heji is effective and safe in improving the heart function of Type Ⅱ diabetic patients with cardiac insufficiency.