Abstract: During the years 1985 to 1991,we made investigations on the fauna and ecology of fleas on Mt.Gaoligong.A total of 47 species which belong to 23 genera of 5 families were obtained.According to the vegetation and elevation altitude above sea level,the Mt.Gaoligong was divided into 5 (in eastern slope) and 4 (in western slope) vertical zones.Among these zones,the highest number and diversity indexes of species of the fleas were in Ⅲ zones (Cool-temperate coniferous and broadleaf mixed forest,2500-3000 m in eastern slope and 2950-3100 m in western slope),and the lowest in Ⅳ and Ⅴ zones (alpine bush,that is 3100-3600 m in western slope,and 3500-4000 m in eastern slope).On the other hand,the fleas fauna of Mt.Gaolgong shows a high degree of endemicity (32 endemic species account to 70% of total species discovered).Based on the distribution of the main Palaearctic and Oriental and endemic alpine species,could be considered the typical species of Oriental region as main distribution below the altitude of 2800 m (in eastern slope) and 3000 m (in western slope),the opposites belong to Palaearctic;the zone in about 2800 m (Cool-temperate coniferous and broadleaf mixed forest) was the division line between the two regions of Mt.Gaoligong.