Cold and hot damages which are both common disasters occurring in DSER growth time in lower-middle reaches of the Yangtze River Basin harm early rice. The two disasters occurrence should be deeply studied to protect the DSER yield. This study was based on meteorological data of 48 agricultural meteorological stations during 1961-2010 period and agricultural meteorological data during 1981-2010 for DSER in lower-middle reaches of the Yangtze River Basin. In this study, the growth time was divided into several phases according to the growth stage, including tillering stage, booting stage, flowering stage and filling stage. The disasters taking place at some stages was identified by building new judging standard and their intensity value was calculated by harm accumulated temperature calculation model. Fisher optimal division method was used to classify the disasters and H-P filter was used to consider the reduction of the yield. It was conducted to analize the disasters’ characteristics in growing season, the intensity of hazard and the weight of hazard at each stage by judging and quantifying cold and hot damage and developing hazard assessment model of disasters. All findings were displayed in maps by GIS technology. The results showed that: ①New disaster judging standard was more suitable for DSER and the hazard assessment model could reveal the disaster situation in lower-middle reaches of the Yangtze River Basin. ②Cold damage was severe at tillering stage while hot damage was severe at filling stage. In the view of the distribution of the decadal disaster intensity, cold damage became to be weak and hot damage became to be strong. Compared with the plains, mountainous region and hilly ground were attacked by cold damage frequently and hot damage rarely from the perspective of spatial distribution of disasters. Distinctly, plains near large areas of water were often harmed by cold damage at booting and flowering stage. ③The area of high hazard value and high disasters value at each stage were overlapped by each other roughly. Studying the hazard of the whole growth season showed that the highest hazard value was in Zhejiang province, and the next in Hubei Province. So Hu’nan and Jiangxi Provinces were quite suitable to grow DSER. ④In contrast with the hazard weight at each stage, the vulnerable phases of the whole growth time were in sequence of filling stage> tillering stage> flowering stage > booting stage. What’s more, aiming at defensing and fending off risk, some special stages in special province should be paid close attention including booting and filling stages in Hubei Province, tillering and flowering and filling stages in Hu’nan Province, tillering and filling stages in Jiangxi Province, flowering and filling stages in Zhejiang Province. The conclusion can be taken as theoretical basis for the government management of agricultural production, disaster prevention and mitigation.