Abstract: Experiments on interaction between intense femtosecond laser and high-purity gold were performed on the SILEX-Ⅰ laser facility. The single-photon counting X-ray CCD camera was used to measure the L-shell X-ray emission from Au plasma at different laser power densities. The experimental results show that in the process of Au plasma X-ray emission, the high-speed electrons result in the intense bremsstrahlung and thermal radiation, and all the radiation intensity increases with the laser power density.