Abstract:On the basis of Logistic model, a normalized comprehensive heat injury index that can be accumulated is applied in studying the high temperature events and assessing their impacts on single rice yield. The results show that the northern west part of Yangtze Huaihe River Valley is the critical zone of rice yield loss due to heat injury through the analysis of the relationship between the heat injury index and rice yield loss. In this region, the average loss rate increases notably from 8.9% in 1970s to 17.9% in 2000s with the expanded loss areas. Rice flowering stage concentrates in the period of high temperature, which is the main cause for rice yield loss. Heat injury indexes and affected areas of high temperature reach their maxima respectively in 1960s and 2000s. An abrupt change occurs in 1971 for high temperature covered proportion. Since then high temperature covered proportion increases continuously and gets to 63.6% in 2000s. High temperature events concentrates in the period of 11 July and 15 August every year with 〖JP2〗proportions of more than 20%. With considering comprehensively the end dates of stable temperature above 20℃, concentrated period of high temperature, climate change and the successful experience of avoiding high temperature in the southeastern part of Yangtze Huaihe River Valley, we suggest that late maturing rice be promoted and its sowing date be delayed to May. These measures can ensure the flowering stage to occur in the period between late August and early September, avoiding the high temperature damages.〖JP〗