Abstract: Elite inbred lines with high combing ability are the key factor in corn(Zea mays L.) breeding. Our objectives were to examine the combining abilities and genetics parameters in 12 selected inbred lines in a diallel crosses to identify candidates for promising hybrid combinations and develop breeding strategy for germplasm improvement in early spring corn utilized in the northeast of China. The crosses were tested by random complete blocks methods, several agronomic traits in ear and kernel were evaluated, and data were analyzed in Griffing’s method IV for complete diallel crosses design. The combining ability analysis of diallel data showed highly significant effects for general combining ability (GCA) and specific combining ability (SCA) in tested traits of selected parents. Ear Diameter, Kernel Density and Kernel Rows of Ear have relative higher heritability and mainly controlled by additive effect; Grain Weight of Single Ear and Plot Yield have relative lower heritability, because non-additive effect take a larger portion in inheritance, these traits tend to affected by environment factors. Several parents can impact the corresponding trait in their offsprings remarkably, K12, Dan 340, HS169 can increase yield, P138 help to improve Kernel Density，local inbreds LK118 and Big Yellow Kernel conduce to prolong the length of ear respectively.