Abstract: Forward-and reverse- subtractive cDNA libraries between Longissimus Dorsi of Largewhite and F1 of Meishan×Largewhite pigs have been successfully generated by means of suppression subtractive hybridization(SSH), and both of them were subject to the determination of subtraction efficiency that proved to be approximately 2¹⁵-and 2¹⁰-fold indicated by β-actin as an index. PCR analysis of the total of 700 and 623 positive clones obtained from the corresponding plasmid libraries demonstrated that the cDNA inserts range in size largely from 150 to 600bp. It is safe to say that the construction of forward- and reverse- subtractive cDNA libraries between muscle tissue of parents and progenies lays groundwork for isolating and identifying genes with respect to heterosis.