Abstract:Based on previous researches and analysis of the characteristics of sunlight, temperature, and water required for rice growth in Jiangsu, it is put forward that the evaluation indexes of climatic suitability for rice are the length of suitable growth period, cumulative precipitation, active accumulated temperature of t≥10 ℃, and sunshine duration from May to October. The regionalization factors and grading thresholds of climatic suitability for rice in Jiangsu are established in combination with the existing rice-wheat or rice-rape double cropping system. Based on the meteorological data of 85 stations (cities and districts) in Jiangsu and its surrounding areas from 1961 to 2019, an evaluation model of climatic suitability for rice is established by using fuzzy comprehensive evaluation method, and the comprehensive evaluation index is calculated. Then the planting area of rice in Jiangsu is divided into 4 zones of medium-ripening medium japonica, late-ripening medium japonica, early-ripening late japonica, and medium-ripening late japonica by using the natural breakpoint method of ArcGIS. The interdecadal analysis under the scale of 30 a shows the suitable planting areas of the 4 rice varieties are adjusted due to the extension of the suitable growth period and the increase of active accumulated temperature, among which, the planting area of late-ripening japonica rice is expanded to the south of the Huaihe River.