Abstract: The total RNA from heart tissue of Yunan pig was extracted by isothiocyanate method in the trial.Firstly,full-length cDNAs were synthesized by SMART technique,then a pool of double-stranded cDNA was amplified by LD-PCR technology.The achived cDNA fragments was ligated into pMD18-T vector and transformed into E.coli DH5α to construct the full-length cDNA library.The library was tittered,and the rate of recombination（blue/white） was also determined.The results showed that the primary titer of the constructed cDNA library was 1.8×105 cuf/mL,the recombination rate was about 94.4% .13 transformed germs were selceted and cultured,then their plamids were extracted and identified by restriction enzyme of Hind Ⅲ and EcoRⅠ,the gel electrophoresis showed the length of most cDNA inserted in the library was about 0.3-2.0 kb.