Abstract: Verticillium dahliae Kleb. is a widely distributed soilborne pathogen causing vascular wilt diseases on cotton. It is difficult to control for V. dahliae microsclerotia which is the main inoculum. In this study, the optimum medium of microsclerotium formation and germination were investigated by colony growth rate, microsclerotia quantity, microsclerotia diameter and microsclerotia germination rate. Six different V. dahliae strains collected from Xinjiang were detected. The main results shown that The optimum medium of microsclerotium formation was the oat medium modified, in which the quantity and diameter of microsclerotia was better than the others types mediums such as PDA, PDA modified, Czapek, M1, BM modified called BMM. The amount of microsclerotium in M1 and BMM was more than the others types mediums, however, the diameter of microsclerotium in them was less than that in semi-defined mediums such as PDA, PDA modified and oat medium modified. So, oat medium modified, M1 and BMM were the ideal culture mediums for rapid cultivation of Verticillium dahliae microsclerotia.