An investigation of gamasid mites on the body surface of small mammals wascarried outin Yunnan Province of China from 1990 to 2004. The small mammal hosts werecaptured from 25 counties which represent five geographical subregions, namely MiddleSubregion of Hengduan Mountains, Southern Subregion of Hengduan Mountains, EasternPlateau Subregion of Yunnan, Western Plateau Subregion of Yunnan and Southern Moun-tainous Subregion of Yunnan. The captured 10803 small mammal hosts belong to ninefamilies, 29 genera and 52 species in four orders (Rodentia, Insectivora, Scandentia andLagomorpha). A total of 68 571 gamasid mites were collected from the body surface of thecaptured small mammal hosts and all the gamasid mites were identified to 10 families, 33genera and 112 species. This paper lists all the mite species, together with their taxonomicposition (genera and families) and their corresponding hosts. Much more mite species werefound in the Middle Subregion of Hengduan Mountains than in other geographical subregions.The total individuals of mites and small mammals in the Middle Subregion of HengduanMountains are also the most plentiful in the five geographical subregions. Three dominantmite species and three dominant small mammal hosts were determined as the dominant. species in the investigated areas of Yunnan Province. The dominant hosts are Rattusflavipectus (which accounts for 34.85 % of the total individuals), Apodemus chevrieri (13.43 %)and Rattus norvegicus (10.40%) while the dominant gamasid mite species are Laelapsnuttalli (Hirst, 1915) (27.84%), Laelaps echidninus (Berlese, 1887) (18.38%) and Laelapsguizhouensis (Gu et Wang, 1981) (14.79%). The results showed the high species diversityof gamasid mites in Yunnan Province and the uneven distribution feature in differentsubregions.