【Objective】To develop marker-assisted selection(MAS) technology of RYR1 gene in breeding of Pietrain pig populations, and improve pork quality in pig populations.【Method】PCR-RFLP assay was used to detect the allele frequency of RYR1 gene in 509 Pietrain pigs. The correlation between genotype and phenotype was analyzed using regression model. The correlation between allele frequency and phenotype was analyzed using the Bootstrap method.【Result】The predominant allele (N) frequency of RYR1 gene was 81.73% in the Pietrain pig population. The pigs with NN genotype had better performance in daily gain, the pigs with Nn genotype were better in backfat EBV, maternal and paternal indexes, and the pigs with nn genotype were better in limb trait. Breeding performance was in balance when n allele frequency was 19%. When n allele frequency was above 19%, the pigs had higher lean meat content, thinner backfat, and better body shape. When n allele frequency was below 19%, the pigs had higher growth rate.【Conclusion】When body shape, lean meat content, back fat thickness were more important goals for Pietrain pig breeding, it is suggested to increase n allele frequency in the population. When growth rate, anti-stress, and meat quality after slaughter are more important goals for breeding, it is suggested to purify the predominant allele (N) of RYR1 gene in the population.