To study the function of the starch synthase III (SSIII) gene in synthesis of wheat starch. SSIII partial cDNA sequences (GenBank No. EF466009) from common wheat (Triticum aestivum, Yujiao 2 cultuvar) grains was cloned with RT-PCR. The result demonstrated that the cloned SSIII gene sequences were identified to97% to the reported SSIII genes in GenBank previously. Its antisense expression vector was constructed with pWM101plastid, and RNAi vector was also constructed with pFGC5941 plastid. These constructed vectors would further be transferred into wheat grains through gene engineering way to study the function of SSIII in starch biosynthesis of wheat plants.plants.