Abstract:The “Early indica and late japonica” pattern is an important cropping pattern for double cropping rice in the middle reaches of the Yangtze River,and is of great significance to improve the efficient operation of annual nitrogen fertilizer for reducing the use of nitrogen and the loss of nitrogen to the environment. The early indica rice “Liangyou 287” and late japonica rice “Egeng 403” were used to investigate the dynamic changes of tillers,leaf area index (LAI) and SPAD values,dry matter accumulation in key periods,yield and yield components,and nitrogen use efficiency (NUE) in two seasons. Six nitrogen (basal fertilizer:tillering fertilizer:panicle fertilizer) fertilizer combinations including 3 groups of early rice:N1/N2(6∶4∶0),N3/N4(6∶3∶1),N5/N6(5∶3∶2)),2 groups of late rice:N1/N3/N5 (5∶3∶2),N2/N4/N6(5∶2∶3),and treatment of no nitrogen fertilizer (N0,CK) were set. Results showed that late nitrogen application in early rice significantly increased the rate of panicle bearing tiller,and that of N5/N6 treatment reached 95.5%. N3 treatment of late rice had the highest effective panicle. The leaf area index of early rice under N3/N4 treatment was the highest,42.6% higher than that under N1/N2 treatment. The leaf senescence rate under N3/N4 treatment was lower than that under N1/N2 treatment. The LAI of late rice under N3 treatment was the highest. The yield of N3/N4 and N5/N6 in early rice was significantly higher than that of N1/N2,with the increase of 17.3% and 14.6%,respectively. The yield of N3 in late rice was significantly higher than that of other treatments,and the annual yield of N3 treatment was the highest. The annual agronomic nitrogen use efficiency (AE) of N3 treatment was 43.3% higher than the average of other treatments. The partial production efficiency (PFP) of nitrogen fertilizer of N3 treatment was 11.7% higher than that of other treatments. It is indicated that the ratio of nitrogen fertilizer application for early indica rice was basal fertilizer∶tiller fertilizer∶panicle fertilizer=6∶4∶0,and the combination of 5∶3∶2 for late japonica rice significantly promoted the increase of annual yield and nitrogen utilization efficiency.