To investigate the effects of different feeding methods on gene expression of calpastatin and μ-calpain and shear force in longissimus dorsi muscle of pigs, fifty-four Duroc×Landrace×Large White tribasic hybrid barrows with average weight of about 60 kg were randomly allocated into 3 groups with 3 replicates each and 6 pigs per replicate. The first group was taken as control group with ad libitum feeding, and the second group was taken as compensatory growth group in which feed was restricted by 30% for initial 20 days and then was ad libitum feeding for final 20 days, and the third group was restricted feeding group in which feed was restricted by 30% during whole experimental period. All pigs were slaughtered and samples were collected, and relative abundance of calpastatin and in μ-calpain mRNA in longissimus dorsi muscle of pigs were determined by real time PCR. The results showed as follows: the relative abundance of calpastatin and μ-calpain mRNA in longissimus dorsi muscle had no significant difference between ad libitum feeding group and the compensatory growth group (P>0.05), and there was significant difference between the compensatory growth group and the restricted feeding group (P<0.05), and between ad libitum feeding group and the restricted feeding group (P<0.01). The shear force of longissimus dorsi muscle was positively correlated with calpastatin mRNA significantly (correlation coefficient=0.505 9). There was negative correlation between shear force of longissimus dorsi muscle and relative abundance of μ-calpain mRNA (correlation coefficient=-0.475 7) and between relative abundance of calpastatin mRNA and μ-calpain mRNA (correlation coefficient=-0.055 9). It was concluded that compensatory growth and restricted feeding both strengthened regulation of calpastatin and μ-calpain gene at transcriptional level.［Chinese Journal of Animal Nutrition, 2010，22（3）:640-646］