In order to investigate the resistant molecular mechanism of corns against gray leaf spot, resistant in-bred 78599-1, OH43Ht N and susceptible inbred Ye478, K12 were used to screen differential expression genethrough DDRT-PCR when 6 leaf stages inoculated. The differential expression genes were tested by RT-Northernand the positive clones were sequenced. Results showed that there were 6、5、5 and 3 positive genes in 78599-1,OH43Ht N and Ye478, K12, respectively. The 6 differential expression genes were selected as candidate genesthrough the blast analysis of the 19 differential expression genes. The homology research indicated that candidategenes were highly homological to Zea mays MTN3, CONSTANS-CO5, abscisic acid receptor（PYL） and Co A with97%, 99%, 97% and 100% identity, respectively. The two unknown candidate genes were highly homological toZea mays hypothetical protein with 99% identity. This study would provide some useful information for molecularbreeding resistant to gray leaf spot.