Abstract: The eggs,larvae,pupae,and adults of Tribolium castaneum firstly experienced variable thermal acclimation at different heating rates(0,10,5 and 2.5℃/h) from 28℃to 50℃,then they were treated at 50℃for different times(0,15,30,45 and 60 min),and their mortality were investigated.The results showed that different treatment times and different heating rates significantly affected the mortality.When treated at 50℃for 0-30 min,the mortality of T.castaneum eggs with acclimation was significantly lower than that of T.castaneum eggs without acclimation.When treated at 50℃for 15-30 min,the mortality of T.castaneum larvae with variable thermal acclimation at 2.5℃/h was lowest.When the treatmet time was 30 min,the mortality of T.castaneum pupae increased with the decreasing heat rate.When treated at 50℃for 15 min,the mortality of pupae acclimated at 2.5℃/h was 93.33%,which was significantly higher than other groups.The mortality rate of Tribolium castaneum adults increased with the decreasing heating rates.