Japonica rice cultivars in the Yangtze River Basin have seen improvements in grain quality over the past 60 years, with better milling, appearance, and cooking qualities. However, the protein content has decreased, affecting the nutritive value. The use of nitrogen fertilizer has shown to decrease grain quality, particularly in terms of eating and cooking quality. Higher nitrogen levels lead to higher protein content but lower amylose content, impacting starch properties. Overall, the study suggests that both breeding and cultivation practices, especially nitrogen and water management, are crucial for further enhancing grain quality in rice.