Abstract: In diode pumped Nd:YAG lasers,the quantum defect is the most important parameter determining the thermal load of the laser crystal.This can be reduced dramatically by direct pumping into the upper laser level.A bar diode stack with central wavelength of 885nm was used to pump a Nd:YAG crystal with 55mm in length and 5.5mm in diameter.Compared several output-couplers,the maximum static pulse energy of 138mJ was obtained with 58% transmittance and the corresponding optical-to-optical efficiency was 12%.The results show the possibility of 885nm diode direct pump,also it is helpful for the project's process.