A population with 237 F2∶3 families from the crossing of Zong 3×HB 522 was phenotypically evaluated at two locations to assay the genetic characteristics of six grain yield-related traits of maize (Zea mays L.).Results showed that the kernel row number and the ear diameter had higher broad-sense heritability (H2b),followed by kernels per row,kernel weight per ear,ear weight and ear length.The descending order of mid-parent heterosis of six traits and the over-parent heterosis in F1 generation was the kernel weight per ear,ear weight,kernels per row,ear length,row number and ear diameter.Obvious depression of inbreeding were observed in F2∶3 families.The coefficient of variation (CV) of kernel weight per ear was the highest,CV of the other five traits was as follows:ear weight,kernels per row,ear length,row number and kernel weight per ear.The kernel weight per ear was significantly correlated with the ear length,ear diameter,row number,kernels per row.Kernels per row were more effective in promoting kernel weight per ear.Results provided a method for estimating phenotypic values of target genes by using the correlation among six grain yield related traits of maize,thus helped to conduct fine mapping of related genes and gene cloning in maize.