Abstract: This paper analyzed the effects of reciprocal crosses on main agronomic characters and yield of 9 main maize inbred lines and 72 F1 generations in China southwest, using randomized trails. The results showed that, the effects of reciprocal effect on agronomic characteristics and yield were different on maize hybrids with different parents. T-test results showed that, the differences of individual agronomic characteristics and yield were not significantly. The differences of ear diameter, 100 grains weight, weight per era, power of breaking resistance of first inter-node below ear were significantly or very significantly on reciprocal maize hybrids crossed by inbred lines such as Hai9-21, 5003, 478. Thus, the heterosis in individual traits and yield of F1 generation crossed by different inbred line was different, the heterosis in era height/plant height was negative. The negative heterosis in era height/plant height brought out that the ear height/plant height of F1 generation was lower than the mean value of parents. So in the selection of maize inbred lines, do not pursuit of lower ear height/plant height value of parent material.