The development of new laser media promotes the laser properties, but it brings some new problems. It can not be denied that the new laser medium such as Nd:YVO 4 improve the laser efficiency, but as we study its thermal effect, we find the non axial symmetry for its anisotropic thermal conductivity. Basing on the early thermal effect study of the diode end pumped laser medium, we put forward a mechanism of the thermal effect of the laser diode pumped anisotropic medium for the first time, and study the influence of the anisotropic thermal effect on laser properties.