Abstract: In this paper, the shearing basic flow is introduced into the CISK theory developed by Charney and Eliassen (1964).Then, the growth rate of typhoon depression is investigated with a simple numerical model under the effect of cyclonic shearing basic flow in lower troposphere and the effect of shearing basic flow in upper troposphere. The cyclonic shearing basic flow in lower troposphere increases the growth rate. It is explained with dynamic point of view that the enhancement of equatorial westerly or southwest monsoon and the influnce of cold front with moderate strength are conducive to generation and development of Typhoon. The effect of anticyclonic shearing basic flow in upper troposphere is condu- cible for development of Typhoon. But, the cyclonic shearing basic flow in upper troposphere will depress Typhoon. The effects of ambient flow in upper troposphere are wean on development of Typhoon.