Heilongjiang Province has a vast area with a complex and diverse climatic environment and significant differences in cumulative temperatures among regions, which brings challenges to the breeding and large-scale promotion of rice varieties. Longjing 31 is the japonica rice variety with the largest annual spreading area in China and the largest cumulative spreading area since the 21st century. This variety broke the dominant position of Kongyu 131 in Heilongjiang for 10 years with its advantages of high and stable yield, disease resistance and cold resistance, wide ecological adaptability, excellent quality and endurable storage. Based on the current situation of japonica rice breeding in Heilongjiang Province, the paper in-depth analysied the reasons for the large area popularization of Longjing 31 aiming for guiding the future rice breeding.