Abstract: Ornithine decarboxylase (ODC), arate-limiting enzyme in polyamine synthesis,is involved in several biological processes. PCR-RFLP was established to detect genotypes of ten SNPs (six for jlODC1a and four for jlODC1b) in about 900 individuals from 12 Cyprinus carpio var. jian families. The minimum allele frequency (MAF) was 0.140.48. The correlation between the genotypes of ten SNPs and body weight gain indicated that there are seven SNP loci in the female and four SNP loci in the male , and that the body weight gain is associated with the quantity of the SNPs. The individuals with four markers grew obviously faster than those with 03 markers, and grew 14% faster than those with 0 markers, which also reflected growth as a quantitative trait. The diplotype analysis of the screened SNPs demonstrated that individuals with four heterozygous advantage genotypes 4567 (XXXXXXACCTCTCT) were the fastest growth ones that were 26.6% faster than 0 advantage genotype individuals, which could be used in the fast-growth jian carp molecular breeding. Moreover, the diplotype analysis explored the exist of either antagonistic or synergistic interaction between different loci, suggesting that the choice of mutually synergistic advantages genotype and as much as possible SNP markers could benefit the future breeding programs.