In Hexi irrigation area of Gansu Province managed for eight year corn seed production, field test method was used to study the relationships among soil improved special fertilizer, physical properties of seed production cornfield and corn economic traits and benefits. Results showed that the factors affecting corn production followed the order of CO(NH₂)₂>(NH₄)₂HPO₄> PVA and ZnSO₄·7H₂O. Best combination for the factors is 30kg/hm ² PVA, 736kg/hm² CO(NH₂)₂, 420kg/hm²(NH₄)₂HPO₄ and 52kg/hm²ZnSO₄7H₂O. Withthe increases of soil improved specific fertilizer, corn field total porosity, capillary porosity, non-capillary porosity and aggregates increased, but bulk density decreased. When soil improved special fertilizer application increased, corn botanical traits, economic traits and yield increased, but yield increment by unit(1kg) amount of soil improved special fertilizer decreased gradually withthe increase of soil improved special fertilizer, showing the law of diminishing return. Withthe increased amount of soil improved special fertilizer, marginal corn yield and profit in the reduced profit margins. The additional 337.50kg/hm² application rate over the 1350kg/hm² soil improved special fertilizer made revenue to be negative. The optimum economic fertilization capacity was 1350.01kg/hm² and theoretical corn yield was 6700.99kg/hm².