Abstract:The known occurrence of grapevine flavescence dore(FD)and the known distribution of its insect vector, leafhopper Scaphoideus titanus Ball,were extracted from published literatures.This information was summarized in a database file,and then introduced into the bio-geographical information system software DIVA-GIS.The 19 bioclimatic variables of the WORLDCLIM database were evaluated based on the biological characteristics of S.titanus.Three bioclimatic variables were selected for prediction because they were considered the best representatives of the climatic requirement of S.titanus, i.e.mean monthly temperature range (lower+upper), min temperature of coldest month (upper) and max temperature of warmest month (lower).Using the known distribution of S.titanus in Europe as the source data,the above three bioclimatic variables as parameters, BIOCLIM as algorithm, the distribution of S.titanus in North American was analyzed in order to test whether these parameters are appropriate or not. The results rev- ealed that the Great Lakes region of USA and Canada and the Finger Lakes region of New York State were the best habitat for S.titanus. This is exactly true because S.titanus is actually originated from these regions and therefore confirm us that the above parameters are appropriate. Then, the potential distribution of S.titanus in China was predicted using the above parameters. The results show that the vast area of middle and eastern China (101 -124°E, 23 -42°N) is the potential distribution region of S.titanus.Besides, S.titanus can also survive in the vicinity of Shihezi, Xinjiang Uygur Autonomous Region and the middle mountain area of Taiwan Province. Further analysis revealed that the potential distribution region and best habitat of FD phytoplasma are identical with those of S.titanus. Among the ten main viticulture regions of China, the Shandong and Liaodong peninsula of the Bohai gulf viticulture region, the Yunnan plateau viticulture region and part of the Gansu viticulture region are the most endangered areas by FD and S.titanus. As the consequences of global warming, the potential distribution regions of FD and S.titanus in China will shift north within the coming 50 years. Meanwhile, their potential distribution within the Bohai gulf viticulture region will expand remarkably.