The paper uses the data of average air temperature, relative humidity and wind velocity from Yongshun Meteorological Station in every month from 1971 to 2000 as the factors of driftage comfortableness to evaluate the climate environment for Mengdong River tourism spots in Hunan which is a fourstar route as one of the only two driftage routes all over the country by means of fuzzy mathematics, and based on the model the forecast equations are set up. The results showed: (1) It is suitable for driftage from March to November in every year. The climate conditions are relatively comfortable from May to September, the most comfortable time is from June to August. July and August are the peak season for driftage. (2) The correlation degree is 0.859 between the judgment result of climate comfortableness and tourist traffic, showing that meteorological factors are the most important factors that affected tourist traffic. (3) Based on fuzzy evaluation the forecast equations were established for the comfortable level of meteorological conditions in the paper. In practice, it can provide guidance for the tourists drifting.