The SP gene of Rice stripe virus(RSV) isolates collected from Dali,Luliang,Luquan,Shilin,Yuxi,Baoshan and Yiliang of Yunnan Province was amplified by RT-PCR.The amplicons were then cloned and sequenced.Sequence analysis showed that the SP gene was comprised of 537 nucleotides.Molecular variation of the SP gene of the seven RSV isolates was analyzed and compared with that of other RSV isolates released in GenBank.Comparison of the amino acid sequences of the SP gene of different viruses demonstrated that RSV was most closely related to Maize stripe virus(MStV),and RSV has the farthest relationship to Rice grassy stunt virus(RGSV) in the genus Tenuivirus.