Markerassisted selection (MAS) technology could realize direct genetic selection, but it must base on QTL mapping. Genomic selection (GS), as the newest MAS method, has much advantage compared to traditional MAS technology，especially QTL mapping not necessary. In this paper, the factors affecting prediction accuracy of GS were reviewed, including training population type, prediction model, marker number, population size, population structure, hereditary of traits and so on. The application of GS in maize breeding was also introduced as well as hybrids performance prediction. We then predicated the future research and application of GS in maize breeding.