Abstract: In order to screen some potential oleous fungi, fungus tissue of healthy bark, phloem, sapwood and leaf from five Populus were isolated, and detection mycelia and grease content in spore. The results showed that there were 4501 fungus colonies from 4674 poplar tissues, accounting for about 96.3%, and bacteria colonies accounting for 3.7%. Among of them, nooleous fungal colonies were 4043, accounting for 89.8%, and oleous fungal colonies were 458, accounting for 10.2%. The authentication results of oleous fungals by morphological characteristics showed that, these oleous fungals belonged to Zygomycota, Basidiomycota and Deuteromycotina, and 80% of them belonged to imperfect fungi. Among them, Fusarium solani was a fungus with high oil yield. No correlation between the fat producing fungi appeared and Populus species and seasonal, but correlated to the fungal species.