Distribution maps of ET0 during rice growth season, day of growth period (DGP), crop water requirement (ETc), effective precipitation (Pe), coupling degree of ETc and Pe, and their climatic tendencies during 1970s, 1990s and 2010s were calculated and drawn by Penman-Monteith method and Arcmap spatial analysis based on daily meteorological data in 1960—2015 of 26 meteorological stations and crop coefficient of 29 rice irrigation experimental stations in Heilongjiang Province. The result showed that the average ET0 during rice growth season was 620mm, it was decreased firstly, and then increased from west to east, the decrease of wind speed, humidity, sunshine hours and the increase of temperature led to the decrease of ET0 at a climatic tendency of -3.90mm/(10a). The average DGP was 115d, and it showed an increase trend from north to south, the increase of temperature caused DGP to increase at a climatic tendency of 2.68d/(10a). The average Pe in rice growth period was 297.03mm, which was increased firstly and then decreased from west to east, the increase of DGP compensated for the decrease of rainfall, and the Pe was increased at an average climatic tendency of 0.62mm/(10a). The average ETc was 490.52mm, which was decreased firstly and then increased from west to east, the increase of DGP compensated for the effect of ET0 on ETc, and the ETc was increased at an average climatic tendency of 6.66mm/(10a). The average coupling degree of ETc and Pe was 064, which was increased firstly and then decreased from west to east, the increase of ETc was larger than that of Pe, 〖JP3〗which made the coupling degree of ETc and Pe decrease at an average climatic tendency of -0.009/(10a). The research result provided a basis for rational allocation of irrigation water resources and rice variety layout in Heilongjiang Province.