In order to analyze the characteristic of Ho3+ in CTH∶YAG during the stimulated emission,the effective inversion reduction factor which reflects the utilization rate of the effective population inversion has been introduced into laser rate equation to substitute the inversion reduction factor.The numerical simulation of the effective inversion reduction factor of CTH∶YAG (γ*CTH∶YAG) shows that γ*CTH∶YAG is a nonlinear increasing function of the temperature (T),and has an inflexion near the cooling water temperature,which brings an approximate linear increasing area.There is 1＜γ*CTH∶YAG＜1.5 in the temperature range in which the laser can work,and γ*CTH∶YAG is closer to 1 around room temperature.In addition,γ*CTH∶YAG is also affected by the change of transition stark level,but the effect doesn′t change its main characteristic relating to temperature.The analysis show the meaning and characteristic of γ*CTH∶YAG,which provide a theoretical evidence of temperature sensitivity of CTH∶YAG system,and is useful for optimizing the output pulse.