Abstract:This study used homologous sequence cloning method to clone the full length of sucrose phosphate synthase gene in Dendrobium officinale and induce prokaryotic expression.Results were as follows:(1)The cDNA is 3 502 bp in length containing an open reading frame of 3 186 bp encoding 1 061 amino acids.The GenBank accession number is JF423929.On the amino acid sequence level,this gene shows the highest similarity (93%) with SPS gene of O.goldiana.The similarity of SPS gene were higher than 60% with other plants.(2)The gene was expressed in E.coli with molecular mass of 118.7 kD,which was consistent with the speculation of Biotech.(3)Secondary structure includes helix,beta-folding and coil,which is a hydrophilic,transmembrane and unstable proteins.There are two function structure domains which are sucrose synthesis functional domain and glycosyl transfer function domain.This study provides the theory basis for research the gene spatio-temporal expression and function,polysaccharide synthesis mechanism and metabolism path in D.officinale.