The immersion gold process based on electroless Ni-P alloy substrate with three P contents (4%, 9% and 11%) was investigated by X-ray fluorescence spectrometer, atomic force microscopy and open circuit potential measurementand analysis. The effects of temperature on the gold deposition process were also discussed. The results show that the deposition rate and electrode potential are changed during the immersion gold process. In the same temperature, a higher P content often leads to a high electrode potential and a low initial deposition rate. However, the effect of temperature on immersion gold is relatively complex. In the range of 50-80℃, a high temperature results in a positive potential and a better surface morphology of the gold coating with a smaller surface roughness, while a more negative potential and a bigger surface roughness are obtained at a higher temperature(90℃).