Abstract: Paraoxonase-2 (PON2) gene production is an antioxygen for the metabolism of circulating triacylglycerols. It is considered to be a major candidate gene affecting fat deposition in blood vessel and human lifespan, respectively. In this study, direct sequencing method was used to detect the single nucleotide polymorphisms in the exons of PON2 gene; polymerase chain reaction-singlestrand composition polymorphism (PCR-SSCP) was applied to analyze the polymorphisms of exon 9 of the PON2 gene in 478 cattle that comprised of seven breeds, namely Luxi, Nanyang, Jinnan, Chinese Simmental, Holstein, Murrah buffalo and Nili-Ravi buffalo. Four single nucleotide polymorphism sites were discovered in exons, which had not caused the change of amino acids. A 167 bp long PCR product of exon 9 was detected with SSCP. BB genotype had one substitution mutant T98C. Except Luxi and Holstein, other five breeds were all at Hardy-Weinberg equilibrium (P > 0.05). In Luxi, Nanyang, Jinnan and Holstein, the polymorphisms information contents were moderate polymorphisms (0.25 <PIC< 0.50). Others were in low polymorphisms. AA genotype was not detected in Murrah buffalo and Nili-Ravi buffalo, while AA, AB and BB genotypes present in other five breeds. The predominated frequency of the genotypes were difference in these seven breeds, AA>AB>BB was in Luxi and Nanyang; AA/AB/BB was near to 1∶1∶1 in Jinnan; there was serious skewness of BB in Chinese Simmental, which was the predominated genotype and the allele B was the dominance allele; and in two Buffalo breeds, B allele was the superiority. According to statistical analyze with SAS 9.1 GLM procedure, there were significant difference between breeds and genotypes (P < 0.); and no significant difference were found among several age groups in Luxi cattle (n=238) between genotypes (P > 0.05), but significant difference among different genotypes was found (P < 0.01). Combination with the tendency of the development of the genotype of animals, the AA type will be the fitted one for longer lifespan.