Hybrid maize grown in dyked area in An Giang mostly is under undeposited condition. Moreover, farmers in this area have not considered adding enough primary and secondary nutrients to the soil, therefore crop quality and yield may be reduced. The field experiments have been conducted during dry season 2013-2014, objective of the study was to determine effect of applying N, P, K, Ca and Mg on yield of hybrid maize grown under undeposited alluvial soil at An Phu-An Giang. Results showed that applying enough primary and secondary nutrient elements (N, P, K, Ca and Mg) would give the yield at Khanh An (13.0 tons/ha) and Quoc Thai (14.0 tons/ha) higher than that of farmer which were 12.2 and 13.4 tons/ha respectively. Using omission technique with P, K, Ca and Mg in 24 farmer's maize fields showed 41 to 62 percent received response yield as much as 1.7-2.3 tons/ha. Yield responses to nutrient application at An Phu followed the order NPKCaMg.