Abstract: In order to establish Agrobacterium tumefaciens -mediated transformation system of Polygonum cuspidatum shoot tip, some key factors that affect transformation frequency of P. cuspidatum shoot tip were studied. The shoot tips of P. cuspidatum was infected by Agrobacterium tumefaciens EHA105 with the plasmid which contains PcRS gene. The superior transformation system was as following, pre-cultured 2 days and then infected 10 minutes in suspension（OD₆₀₀=0.6）, co-cultured 3 days, transgenic tissues and shoots were selected with 8 mg/L hygromycin. Six transgenic plants from 300 explants were obtained and the intergration of transgene was confirmed by PCR and Southern blot analysis.