Abstract: 【Objectives】The mechanism of film mulching on spring maize grain yield, N accumulation, N use efficiency and soil available nitrogen spatial and temporal variations was studied under different N application rates, to provide theoretical basis for the practical use of the film mulching technology on spring maize in the middle reach of Yangtze River. 【Methods】 A split-block field experiment was conducted with film mulching(F)or no film mulching(NF)as main factor and N application rates as the deputy factor: N0, N135, N202.5, N270 and N337.5. Plant samples were collected at jointing, silking and maturity stage of maize, the N contents were determined and the nitrogen accumulation amount(TNAA)and agronomy nitrogen use efficiency(ANUE)and nitrogen recovery efficiency(NRE)were calculated; at the same stage, soil samples of 0-20, 20-40 and 40-60 cm in depth were collected, and the NO-3-N and NH+4-N contents were analyzed. The yield and yield components were investigated after harvest. 【Results】There were significant differences of film mulching and N application on grain yield, ear number, ear kernels number and 100-kernel weight. Compared with NF, film mulching significantly increased grain yield by 23.0%-45.9%(P0.01), the main reason was that the ear kernels number were increased by 7.6%-37.0%(P0.05)and 100-kernel weight increased by 0.5-2.1 g(P0.05). N application significantly increased grain yield of spring maize by 102.2%-168.6%(P0.01), the main reason was the increase of ear kernels number(60.2%-125.0%,P0.01), instead of the ear number and 100-kernel weight. Spring maize TNAA was increased significantly by film mulching and N application in the tested growth stages, but the interaction of the two experimental factors was only showed at silking stage. Compared to NF, film mulching increased the ANUE by 45.32%-164.23% with different N application rates, but not significant on the NRE(2.34%-17.64%). The ANUE and NRE were respectively increased by 26.21%-43.71% and 26.75%-47.20% with N application. There were still no significantly interact effects of film mulching and N application on ANUE and NRE. Film mulching increased fertilizer nitrogen releasing rate by increased soil temperature and reduced precipitation in the same stage, so the soil available N contents were significantly increased in the 0-20 cm depth under N 135-270 kg/hm2 levels and 20-40 cm depth under N 202.5 and 270 kg/hm2 levels, and in the 40-60 cm depth soil at V6 stage. 【Conclusions】 The significant interaction of film mulching and N application on the N accumulation at silking stage was beneficial to the increase of ear kernel number, and the N accumulation during kernels filling stage, which promotes the kernel filling and the final 100-kernel weight. Under the experimental conditions, with flim mulching, the N application should be controlled in range of 202.5-270 kg/hm2 in spring maize in the middle reaches of Yangtze River for high grain yield and high nitrogen use efficiency.