Abstract: 【Objective】 The Sugary1 (Su1) gene of sweet corn was analyzed by nucleotide polymorphism analysis and neutral test, and the allelic variation sites of Su1 in sweet corn from different sources were analyzed, which provided a theoretical basis for variety improvement and quality improvement of sweet corn. 【Methods】 In order to illustrate the sequence polymorphism of maize gene Su1, the Su1gene in 170 sweet corn inbred lines was sequenced, using the genomic sequence of B73 as the reference. 【Results】 Analysis showed that 97 nucleotide sites were mutated, including 85 SNPs sites and 12 InDels locus. Among them, there were 12 SNPs loci and 0 InDel in the coding region, 85 SNPs loci and 12 InDels in the non-coding region. There were 5 synonymous mutations at SNP site and 7 non-synonymous mutations in the coding region. The inbred lines were divided into 76 haplotypes according to the full-length sequence of Su1 gene, and 47 haplotypes were divided into 47 haplotypes according to the coding region of the gene. 【Conclusion】 The Su1 gene had undergone obvious artificial selection.