Abstract: The present paper designed a basic structure of tungsten-diamond transmission target, according to the theoretical model of the end-window transmission target for micro-focus X-ray source. The tungsten-diamond transmission target is prepared by magnetron sputtering deposition technology. The microstructure of tungsten film is analyzed by scanning electron microscope. The performance of tungsten-diamond transmission target is carried out on the X-ray tube of YXLON, and the performance is compared to that of YXLON. The experimental results show that the surface morphology of homemade target is similar to that of YXLON. Under the same operating conditions, the X-ray emitting efficiency is slightly higher about one percent than that of YXLON and the corresponding X-ray production power of them is little difference, and the lifetime of homemade target is longer than that of YXLON. All the above mention results indicate that homemade target could be satisfied the application requirements of high quality target for micro-focus X-ray source.