Bone morphogenetic protein 5 (BMP5) gene was suggested to be a potential positional candidate gene for fatness trait QTLs on SSC7. Here by comparative sequencing of BMP5 gene in Meishan (MS) and Large White (LW) pigs, one SNP *131C>T in 3' un-translated region was detected. Association analysis results in 322 LW x MS F(2) pigs showed that CC pigs had thinner back fatness and heavier ham than TC (P<0.05 or P<0.1), and had a higher fat percentage and a lower lean meat percentage (P<0.1) than TT. Moreover, this C/T transition was predicted to alter BMP5 interaction with let-7c and miR-184 by using RNA22 and RNAhybrid. The negative expression of BMP5 gene with let-7c and miR-184 detected from miRNAs overexpression in swine fibroblast, indicating these 2 miRNAs might participate in the translational inhibition of BMP5 gene. Overall, SNP *131C>T might be a good marker for fatness traits.