Abstract: The daily average temperature higher than 30℃,daily maximum temperature higher than 35℃ and lasted over three days were taken as the meteorological indexes of the high temperature induced heat damage for early rice in Zhejiang Province.Based on these indexes and maximum temperature data observed in 68 observation stations in Zhejiang Province,the high temperature induced heat damage and its impacts on early rice yields were analyzed.The results showed that the high temperature induced heat damage for early rice occurred in the most regions of Zhejiang Province,except the eastern coastland and the southern mountainous areas,while Jinhua was one of the most serious damage regions.The high temperature induced heat damage had an increased trend since 1988.The duration of the high temperature induced heat damage was positively related to the percentage of empty grain and unfilled grain,while it was negatively related to the seed setting ratio,the thousand grain weights and yield.The simulation equations were established to describe the above mentioned correlations and provided references for monitoring,early warning and evaluation of the high temperature induced heat damage on rice yields.

Key words: High temperature induced heat damage, High temperature induced heat damage, Rice, Yield component, Correlation