Total RNA, mRNA were isolated from baker's yeast S. cerevisiae, the cDNA was prepared with AMV Reverse Transcriptase from the total mRNA. The gene of trehalose-6-phosphate synthase was cloned from the cDNA with PCR amplification. The gene was sequenced and the results showed that the tpsl gene contains 1507 nucleotides and 99.6% identity with S. cerevisiae. The tps1 gene was constructed on the plant expression vector pBin438.