Double-muscling pig is good at meat yielding, but the genetic reason for this trait was not clear till now. A SSH (suppression subtractive hybridization) library was built with cDNA from LD (longissimus dorsi) muscle of double-muscling pigs as tester, and that of non-double-muscling as driver. 686 clones in this library were single insertion. And they were all sequenced. The sequences were BLAST on line with the GenBank dbase, GenBank EST dbase and also the Tigr Porcine EST dbase, 11 of them were not matched in any of the databases which might represent new genes related to porcine double-muscling trait. 3 of the functional genes, which are RYR1, CAMK2 and IGFBP 7, were chosen firstly to do quantitative PCR to confirm the expression differentiation between double-muscling LD tissue and non-double-muscling pigs LD tissue. The genes expressed in the former tissue were 1.87, 1.90, 1.85 times higher, respectively, than in the later tissue. 3 clones of the new ESTs were also detected with quantitative PCR, they were 1.48, 1.44 and 1.78 times higher in the former, respectively. These results implied that new candidate genes could be selected from the SSH library constructed in this research, and this could be a way to make the genetic base of double-muscling pig more clearly.