Different N fertilizer levels were tested on Japonica rice with varying breeding times. Early-selected varieties showed higher sensitivity to N fertilizer, while contemporary varieties had better dry matter accumulation and N uptake. Rice yield increased with N application, with early-selected varieties showing different responses compared to contemporary ones. Plant height decreased with selection time replacement, while grain setting density increased. The relationship between rice yield and dry matter/N accumulation was significant. N utilization efficiency was positively correlated with yield but negatively correlated with plant height and panicle length.