To evaluate the effect of combined biological and chemical nitrogen fertilizers on corn hybrids, an experiment was performed as split plot randomized complete block design with four replications. Main plots were Included: the use of chemical and biological fertilizers in four levels (100% chemical fertilizer, 75% chemical fertilizer + 100% bio-fertilizer, 50% chemical fertilizer + 100% bio-fertilizer, 25% chemical fertilizer + 100% bio-fertilizer) and sub plots included corn hybrids (single cross 704 hybrid, Mobin hybrid and Karoun hybrid). Chemical fertilizers were used include urea, triple super phosphate and potassium sulphate and for biological fertilizer Nitroxin was used. The results showed that the Karoun hybrid in 50% Chemical fertilizer + 100% biological fertilizer treatments had the highest grain yield and biological yield and the highest protein percent and the lowest number of grain per row ,grain yield and biological yield were belongs to 100% chemical fertilizer and Mobin hybrid treatment. The highest 1000 grain weight was belongs to Karoun hybrid and the lowest protein percent was in Mobin hybrid. Single cross 704 and Karoun hybrids in number of grain per row and Mobin hybrid and single cross 704 in grain weight were not significantly different. Single cross 704 hybrid only in percent of protein was higher than other hybrids.