Revealed biodiversity of slime molds of the zonal and intrazonal communities plain area south of West Siberia. Overall, the analysis included the 2581 sample of slime molds belonging to 178 species. Revealed two new species for the territory of Russia – Dianema nivale (Meyl.) G. Lister (this species was previously known from England, Denmark, Italy, Japan, India), Perichaena brevifila T.E. Brooks et H.W. Keller (this species was previously known from Kazakhstan, the US and Japan).Key words: myxomycetes, slime molds, biodiversity, taxonomic structure, West Siberia.