Abstract: A field experiment was carried out on typical Ust-Sandiic Entisols soil in semi-arid area to study the effect of film mulching, nitrogen (N) application and supplementary irrigation on spring maize (Zea mays L.) yield, soil mineral N (NO3--N and NH4+-N) and N balance. The result showed that in the 0-100 cm soil profile, with the depth of soil layers increasing, NO3--N content before sowing and after harvest decreased, NH4+-N increased slowly, and the total mineral N content declined (NO3--N and NH4+-N). It indicated that film mulching and N application did not increase NO3--N accumulation in deep layer. This might be related to the soil’s insufficient N supplying ability. The N apparent losses increased in all the treatments under N application compared to the zero N application treatment. The crop N accumulation significantly increased (P0.05) compared to the no film mulching treatment. In the 80 mm and 160 mm irrigation with film mulching treatments, the N fertilizer use efficiency of maize increased 18.8% compared with no film mulching. This indicated that under the same N levels, low irrigation (80 mm) with film mulching could save 80 mm water. However, the difference of N fertilizer use efficiency between 80 mm and 160 mm without film mulching was not significant. This indicated that film mulching increased N fertilizer use efficiency and decreased N losses under the same N application condition. In terms of grain yields and N fertilizer use efficiency, the recommended management practice would be “film mulching + supplementary irrigation at 80mm + N application at 90 kg/ha ” based on results of this experiment.