Based on daily precipitation data from 78 meteorological stations in Heilongjiang Province from May to September during 1971 to 2018, Temporal and spatial evolution characteristics of crop growth season and its monthly precipitation（from May to September） in Heilongjiang province was investigated by using the mathematical statistics methods. The results showed that the precipitation was generally increasing during the growing season of crops in the study area, and the trend of precipitation in May, June, July and August was the same as that in growth season, but the precipitation in September was decreasing. During the analysis period, there was a trend that the middle regions had more precipitation in growing season and every month, but spatial distribution of precipitation was slightly different. The precipitation in the growing season, June and August was less in East and West, and more in the middle, and the precipitation in May was less in West, and more in the middle regions and East, and the precipitation in July was less in East, and more in West, and the longitude distribution of precipitation in September was not obvious. The distribution of monthly precipitation during the growing season was parabola type, and precipitation mainly occurred in June to August during summer and was most concentrated in July.