Maize considered one of most important cereals in Egypt that used in consumed directly by humans. It is attacking by different insect pests and most important of these insects, aphids, thrips and corn borer that was influence yield size and quality. Field experiments were planted in early June 2019-2020 seasons at Assiut Governorate. Current study, effects of three fertilizers systems (synthetic, organic and mixture between synthetic and organic fertilizers) and three planting densities (5, 10 and 15 plant/Linear meter) on the population of insects and yield were investigated. Results indicated that mixture fertilizers had lowest mean number and infestation percentage of three tested insects at two seasons. Infestation% was higher in 1^st than 2^nd season. Mean numbers of thrips at mixture fertilizers were a highly significant than both synthetic and organic fertilizers. Addition that, highest yield of maize was recorded in mixture fertilizer at the two seasons (3783 and 3948 kg/feddan, respectively). Results showed that, mean numbers ofthree insect pests were increased with increasing plant density/Linear meter at the two seasons. Thrips population and aphids were significantly differences in threeplant densities (5, 10 and 15 plants/Linear meter) at the two seasons. The highest yield of maize in medium plant density (10 plant/Linear meter) recorded 3655 and 3768 kg/fed., at 2019-2020 season respectively. It is concluded that mixture fertilizer and plant density was 10 plants/Linear meter recorded lowest population of three tested insects and high yield of maize at the two successive seasons.