The study took the Chinese caoyuan red cattle as the research object.The 5 exons of the HTR2A gene were screened for SNP by PCR sequencing.Only two SNPs,S₁ and S₂,were found at the 86 bp and 164 bp of exon 3 The corresponding mutations are g.C86G and g.G164A.Chi-square test shows that S₁ and S₂ are in HardyWeinberg equilibrium.The two detected SNP were analyzed for linkage disequilibrium,and it was found that between S₁ and S₂,D’=0.794,r²=0.350,which is a strong linkage.Two sites（S₁,S₂） formed four haplotypes H₁（CG）H₂（GA）,H₃（GG）,H₄（CA）,and the haplotype frequencies were 0.570,0.234,0.163,0.033,respectively.Combined with meat quality traits for linkage analysis,it was found that the intramuscular fat content corresponding to the haplotype combination H₂H₃individuals was extremely significantly higher than that of the H₃H₃ individuals（P＜0.01）significantly higher than H₁H₂,H₁H₃（P＜0.05）,preliminary judgment of the haplotype combination H₂H₃ is significantly related to the intramuscular fat content of beef cattle,and can be used as a reference marker for breeding beef cattle with high intramuscular fat content.