Objective:To examine the differential diagnosis between physiological and pathological left ventricular hypertrophy by using current echocardiography techniques. Methods:Twenty male SD rats were randomly divided into three groups:One group of rats performed swimming training at high intensive swimming training(HIGH);One group of rats,a 2KIC hypertension was created and maintained(2KIC);And the third rats group was sham operation(control). After 8 weeks,all rats were studied by standard and tissue Doppler echocardiography. Results:Echocardiography showed septal and posterior wall thickness increases in both the 2K1C and HIGH rats. Left ventricular increased by 36% and 41% respectively. Mitral inflow showed a decrease in late-wave velocity,thus increasing the E/A ratio in HIGH rats. However,mitral inflow showed an increase in late-wave velocity,thus decreasing the E/A ratio in 2K1C rats. There was a significant increase in Ea and Ea/Aa in HIGH rats in basal septum and lateral mitral valve annulus. And there was a significant increase in Aa,which led to significant decrease in Ea/Aa in 2K1C rats. Conclusion:Doppler echocardiography parameters of LV diastolic function can be of diagnostic importance for discrimination between pathologic and physiologic LV hypertrophy.