In order to study instantaneous temperature's effects on serum-free medium, following limit experiments are designed, keeping the serum-free medium under different temperature for a long time to study the effects of medium under different temperature on the growth of CHO cells. The results show that 40°C was the best temperature, it also reduces the procedure of medium manufacturing It will provide a theor. basis for the selection of medium producing equipment and production parameters, and improves production efficiency of the equipment.