Based on historical weather data from 1961 to 2010 and future climate data generated by CanESM2 simulation from 2021 to 2070 under RCP emission scenarios, the frequency and occurrence dates of heat stress in different grades during rice growth period in Jiangsu province were analyzed. The results indicated that the spatial distribution of the total number of times and the frequency of different grades during rice growth period for the period of 19612010 were consistently increasing from northeast to southwest. Under three different scenarios, the heat injury events will increase relative to the period of 19612010 and the increases were more under RCP 8.5 scenario than other two scenarios. In addition, the heat stress often occured in late July.