Objective:To analyse the value of cardiac troponin I(cTnI) test and echocardiography in evaluating acute radiation induced heart disease(RIHD) after a single dose radiation in a Newzealand rabbit model. Methods:Each rabbit was irradiated with a single dose. According to the radiation dose,25 rabbits were divided into group A(clinical dose group) and group B(high dose group),then each group was divided into several subgroups according to the radiation dose. The subgroup’s dose and the number of group A was 0,10,14,18 Gy and 3,3,6,7 respectively;the dose and the number of group B was 22,30,40,54 Gy and 3,1,1,1 respectively. Echocardiography and cTnI were detected before and after radiation. The echocardiographic parameters were:① flow pulse doppler Tei index;② tissue doppler imaging:mitral annulus peak velocities in systole (Sa),early disatiole (Ea),late diastole (Aa) and Ea/Aa;③ conventional parameters:left ventricular diameter,ejection fraction(EF) and fractional shortening(FS). Then the pathologic changes of heart were semiquantitatively analyzed after 4 months follow-up. Results:① cTnI began to increase 3 hours after radiation,reached the apex after 14 to 24 hours,then decreased and stayed at a low level about 1 week;moreover,the level of group B was much higher than that of group A; ② after radiation,changes in diastolic and systolic ventricular function were observed with a decrease of Sa,Ea,Aa and a increase of the Tei index;furthermore,with the radiation dose increased,the value of Sa,Ea and Aa deceased,and the Tei index increased. Moreover,there were no changes in the conventional parameters. ③ The average severity grade of RIHD in group A and group B was 1 and 1. 5 respectively. Conclusion:Single high dose radiation can lead severe acute RIHD and the severity is related to the radiation dose.