The aim of this study is to provide certain scientific guidelines for fast cultivation of softshell turtle by investigating effects of water temperature on its heart rate. The heart rate was measured by pH-38 ECG recorder. Water bath was applied to control water temperature, recording electrodes were well attached to four legs of turtle, and the test temperature was controlled within ５～３５℃.The results provide the clear evidence that the heart rate of turtle is linearly proportional to water temperature, but the data indicate that heart rates have the largest variation as the temperature within 26～３0℃ .To identify the optimal growth temperature for other types of aquaticpoikilothermal animals, this paper suggested to measure heart rate as a function of temperature. The temperature that shows large variation may serve as the best cultivated range.The relationship between the heart rate and temperature will provide a quantitative method to quickly identify the optimal growth range for aquaticpoikilothermal animals.