To explore the effects of different ratios of organic and inorganic fertilizers application on rice growth and soil nutrients in the cold and cool regions of Northeast China, this experiment utilized the medium-to-late maturing japonica rice variety Jihong 6 as the test variety and established five treatment groups with varying ratios of organic and inorganic fertilizer since 2017 to conduct long-term positioning test. The results indicated that the combined application of organic and inorganic fertilizers could not only provide stable and adequate nutrients for rice at each growth stage in cold regions, and improve rice grains quality, but also promote the soil accumulation nutrient in paddy fields. Compared with conventional fertilization treatment, the combined application of organic and inorganic fertilizers promoted the formation of effective panicles in rice, increased the seed-setting rate and 1 000-grain weight. Rice treated with the organic fertilizers of 30% and 50% produced yields that were 3.31% and 24.27% higher, respectively, than those under conventional treatments. Compared to conventional fertilization treatment, the combined application of organic and inorganic fertilizers could increase the organic matter and available nitrogen content in the soil, with the available nitrogen content with the organic fertilizer treatment of 30% and 50% being 6.41% and 9.01% higher than that of conventional treatment, respectively. Considering both conditions of rice production and the changes in soil nutrients, this study identified the optimal ratio for sustainable rice production and paddy soil development in the cool regions of Northeast China as: 50% organic fertilizer N+50% chemical fertilizer N+conventional PK fertilizer.