It was studied the grain growth behavior of Incoloy 825 alloy within the temperature range from 1 223 to 1 473 K and holding time range from 0 to 150 min. The influence of the temperature and holding time on the grain size was analysed, and the evolution law of the grain size was studied. The results indicate that the grain size shows no remarkable growth with increasing temperature and holding time when the temperature is lower than 1 373 K. However, the grain size grows obviously with increasing temperature and holding time when the heating temperature is above 1 373 K. The two-stage grain growth model is established on the basis of regression analysis, which can well predict the grain size under different heating temperatures and holding time.