A two-year experiment was carried out at Shalakan Kalubia. Agric. Res. Sta. NRC. Egypt. during 2000 and 2001 seasons. The study aimed to investigate the effect of irrigation. I. at different available soil moisture, (ASM). contents (I40. tea and lag %), nitrogen fertilization levels. (Nico. N110 and N120 Kg Med) and potassium levels (K12. K24 and K3; kg Kzorfed) on maize yield and some of its attributes. A combined analysis was performed for the two seasons. The obtained results showed that most of the differences among means were significant either regarding the independent factors or their different interactions. Gradual and significant increases in grain yield/fed and most of its attributes were observed as the level of any independent factor was increased. The higher grain yield/fed was produced by the combination of irrigation at 80% ASM and addition of 110 kg N/fed along with 36 kg K201fed. Equilibrity among interaction means showed possibilities of replacement among them. With this respect |eo°/e x N100 could replace [40% x N110 Also lao% x Nun x K35 could replace lm‘iii x Nno x K24. Water consumptive use. WCU. differed according to the season and level of irrigation. The calculated WCU ranged between 1942.0 to 2800.0 m3/fed. distributed in 7 to 12 irrigations. Water use efficiency. WUE differed between 1.31 to 1.79 kglm'. according to the level of irrigation. being higher for the lower irrigation level.