An intercross between Meishan and Large White pig population was used to map quantitative trait loci(QTL) for protein percentage in muscle. In the present study, all 135 F2 animals, their parents and their grandparents were genotyped for 24 microsatellites, which were in 1, 2 and 6 chromosome. The marker genotypes were used to calculate the additive and dominant coefficients at fixed position in the genome of each F2 animal, and the protein percentage were regressed on to the coefficients in intervals of 1 cM. Three significant QTLs effects were found for protein percentage in muscle. They were located between markers Sw1332 and Sw2130 at chromosome 1, between Sw2516 and Sw1201 at chromosome 2 and between Sw322 and Sw607 at chromosome 6(P < 0.05), and the explained residual variance were 0.91%, 12.76% and 4.60%, respectively. The results show that QTLs, which affect protein percentage, may be located in different chromosomes.