Abstract: Total RNA of leaf of Lycium Barbarum L. was isolated using guanidinium isothioccyanate and phenol-chloroform. mRNA was prepared by PolyATract mRNA Isolation Systems (Promega). Full-length cDNA was synthesized by Universal RiboClone cDNA Synthesis System(Promega) and then cloned into phage λExcell vector, After Pachage in Packagene Lambda DNA Packaging System, the capacities of the libraries were measured. The capacity of the library was 2.78×105pfu/ml. the recombination rates reached to 88.1%. Heterologous probe of LycB originate from Getina lutea were labeled with digoxingenin-11-dUTP (DIG), were further used to screen the cDNA libraries of leaf of lycium barbarm. Five lycB positive clones was obtained. The recombinants with the cDNA insert fragment were released from the positive clones and were digested with EcoRⅠ, The cDNA fragment were 2.1kb in LycB positive clones. This study will lay foundations for regulating carotenoid biosynthesis via genetic engineening.