Abstract: G3 is an endophytic fungi isolated from root of Juglans regia L... Sequences analysis of ribosomal DNA showed that G3 had the highest homologous with Ceratobasidium. Biological characteristics research showed that the optimum temperature was 25℃, darkness was beneficial to the growth and the optimum pH was 6～7. The optimum carbon and nitrogen source were soluble starch and peptone, respectively. G3 strains could utilize many kinds of carbon source, but preferred organic nitrogen source and acid condition.