[Objective] To investigate yeasts diversity in Qilu Lake and analyze the influence of environmental factors on yeast diversity. [Methods] Yeasts were isolated by in-situ cultivation and analyzed for the D1/D2 domain of large subunit (26S) ribosomal DNA and morphological characterization. We analyzed yeast species richness and species distribution in the Qilu Lake. [Results] In total 321 isolated yeasts were identified to 14 genera and 27 species. Rhodosporidium kratochvilovae and Aureobasidium pullulans were the dominating species in the lake, representing 29.6% and 16.8% of the total strains, respectively. Principal component analysis (PCA) showed that the total phosphorus was an important environmental factor affecting the distribution of Rhodosporidium and the pH affected Cryptococcus yeasts distribution. [Conclusion] There was a high diversity of yeasts community in the Qilu Lake.