Abstract: For further understand genetics background and functional genes of A. tenuissima. A yeast destination vector pRS-DEST42, express foreign genes in a low-copy number in yeast and high-copy in E. coli, was constructed. The entry cDNA library of A. tenuissima was transferred into vector pRS-DEST42 through Gateway system. The cDNA yeast expression library has a higher titer of 2.44×106(cfu/ml) and a total clones of 2.44×107. The rate of positive recombinants clones was 100% and the size of average insert cDNA was 1.38 kb. This provides a basis for isolate and study on functional genes in A. tenuissima.