Single nucleotide polymorphisms (SNP) markers allow rapid screening of crop varieties in early growth stages. We developed a modified SNP PCR procedure for assaying SNPs in maize. For SNP marker development, we chosen 200 SNP sites from MaizeGDB database, and designed two base pair mismatch primers based on putative SNP site of B73 genome sequence. PCR products size was from 200 to 500 bp or was not shown in the case of SNP site existing in Korean silage corns. Using previously discovered 16 primer sets, we investigated distinctness of 50 silage F1 hybrid corns including 10 Korean silage corns developed by RDA such as Gangdaok, Kwangpyeongok, Dapyeongok, Andaok, Yanganok, Singwangok, Jangdaok, Cheongdaok, Pyeonggangok, and Pyeonganok as well as 40 foreign commercial silage corns. From cluster analysis, we confirmed that 10 Korean silage F1 hybrid corns were clearly distinguished except for Singwangok, P1395, and several foreign commercial corns, and selected minimum SNP primer combination for Gangdaok, Jangdaok, Pyeonggangok, and Pyeonganok. Therefore, development of SNP marker sets might be faster, cheaper, and feasible breed discrimination method through simple PCR and agarose gel electrophoresis.