Abstract: A large number of strains of thermophilic actinomycetes were isolated from sediment samples taken from lakes on the Yunnan Plateau. These strains were identified With various methods. Among these strains, four new species are proposed: Saccharomonospora janensis sp. nov., Actinomadura thermoalba sp. nov., Micromonospora thermoflavobrunnca sp. nov., and Micromonospora thermoaurantiaca sp. nov.