Abstract: The paper aims to know genetic affinity about early maturing maize inbred lines of Heilongjiang, reasonably and accurately divide heterosis groups and build model of heterosis. 5 main early maturing corn inbred lines of Heilongjiang Province were selected using NC-Ⅱ design. Combining ability analysis showed that 7 main agronomic traits of 5 main early maturing corn inbred lines had significant difference, genetic index analysis of corn cross combination showed that the ear diameter trait of the cross combination with He344 as female parent had a positive TH (transgressive heterosis), showing powerful heterosis and a positive MH (middle parent heterosis). These results indicated that the effective use of the main early maturing corn inbred lines had very important theoretical and practical value for the corn breeding in Heilongjiang Province or early maturing spring corn region in China. Models of early maturing maize heterosis of Heilongjiang were: heterosis models of Lancaster groups × Tangsipingtou groups, Lancaster groups×Reid groups, Lancaster groups×Hybrid selection groups. The results provided theoretical basis and practice for the efficient use of early maturing maize of Heilongjiang.