This study isolated and identified the yeast strains collected from flowers, leaves and insect frass in Nam Cat Tien National Park based on morphological, physiological and biochemical. characterictics and conserved sequence of Internal Transcribed Spacer (ITS) gene region. Three strains (H5, H7 and H9) from flower, four strains (L5, L10, L24 and L29) from leaf and two strains (P2 and P5) from inset frass were isolated. Morphological, physiological and biochemical data showed that the H5, H9, L5 and L10 belong to Candida genus, H7 strain belongs to Sporisorium genus, L24 belongs to Ustilago genus, L29 strain belongs to Crytococcus genus, P2 strain belongs to Sporidiobolus genus and P5 strain belongs to Williopsis. Sequencing of ITS gene region of these isolated strains showed that similarity between H5 and Candida quercitusa is 94 percent, H9 and Candida quercitrusa is 94 percent, L5 and Candida diddensiae is 89 percent, L10 and Candida naeodendra is 91 percent, L24 and Usalago trichophora is 94 percent, L29 and Crytococcus sp.CBS 8368 is 94 percent, P2 and Sporidiobolus roineniaeis 99 percent, and P5 with Williopsis satumus is 94 percent.