Abstract: For the case of square end faces of the medium,focused Gaussian beam pumping,temperature field of laser medium end-pumped by laser diode(LD) has been studied by using finite element methods.The temperature and its distribution in the medium,such as Nd:YAG,are determined.At last the temperature field at the condition of improving the convective heat coefficient of medium's surface,reducing the coolant temperature or cooling the pumped face of rod is simulated.The results indicate thatit hardly fall the thermal effects by imoroving the convective heat coefficient of medium's surface and reducing the coolant temperature,but it can reduce the thermal effects virtually by cooling the pumped face of rod.