Abstract: To evaluate the effects of water and nitrogen and their interactions on quality traits in grains of summer maize，pool cultivation experiments was carried out in anti canopy of test station for Agricultural Bureau of Weishan County in Shandong province in 2 growth seasons between 2012 and 2013,and cultivar Zhengdan 958 was the tested materials.Effects between normal urea（NU）and coated compound fertilizer（CCF）on quality traits of summer maize in different soil water conditions were researched.Test results showed that at the same soil water condition，protein yield and content of protein，content of crud fat and starch of CCF treatments were significantly higher than those of NU treatment and control.In the same nitrogen fertilizer treatment，protein yield，content of crud fat and starch of soil moisture at 75% of field capacity were higher than those of soil moisture at 50% of field capacity，and protein content was reduced，but protein content of CCF treatments was significantly higher than that of NU treatments.In conclusion，whatever under dry or wet soil，the positive coupling effect of CCF on content of protein，crud fat and starch was higher than that of NU，which could improve grain quality of summer maize very significantly.