In order to develop selected communities with high yield and water stress tolerance, the effect of selection on maize (Zea mays L.) yield and growth improvement was studied under some abiotic stresses (water, nitrogen, and potassium) with four fertilizer combinations (K100 N250, K200 N250, K100 N500, and K500 N200). A field experiment was conducted during six seasons(2009-2011) in the field of Crop Science Dept. – College of Agriculture – University of Baghdad. In this experiment, the synthetic cultivar, Ibaa 5012 was used. The selection depended on seed yield under sufficient and insufficient water. The plants were selected from each group of combination according to phenotypic superiority, and undergone to self-pollination for three cycles under sufficient and non-sufficient water. In the fourth season, the manual random mating was used between selected plants in each group, the resulted seeds from random mating were divided into two groups, which were planted in a comparative experiments for Spring and Autumn seasons under irrigation levels(5 and 10 days), to compare them with the origins undertow plant densities(60 and 80 thousand plant/ha). Results showed the superiority of plants selected from 10 days irrigation. that were selected under SDN1K2 increased ear number by 8% and grain weight by12% .This increase was reflected on grain yield increase for SDN1K2 over original population and all selected plants.WUEc increased by19%. In fall season superiority SDN2K2 in ear number, grain weight, grain yield and WUE by 33%,11%,94%,94% respectively over original population. Selective cycles affected the selections under 5 day irrigation. superiority SDN2K2 ear number increase by 28%,50%. Grain weight increase by7% and 16% for SN1K2 Grain yield increase by 20% and 61% for SN2K1 .WUEc was increased by 23%and 51% in spring and fall seasons respectively. So we recommend the selection for high yield and device lines that tolerant to both of dry stress and high plant density to be used in breeding programs under abiotic stresses and producing improved cultivars suitable to our environments or to be crossed to produce distinguished hybrids.