Abstract:To study the diversity of cultured symbiotic fungi isolated from Galaxea fascicularis L. in the South China Sea. By dilution plate technique and ITS-rDNA sequence analysis to research the diversity of the cultured symbiotic fungi with the coral, determined sequences data were submitted to GenBank and compared with those known sequences. Phylogenetic tree were built up with MEGA 4.0 program. 19 different morphological strains were isolated from surface and inner of the coral Galaxea fascicularis. ITS-rDNA sequences analysis showed that, symbiosis cultured fungi mainly included Aspergillus sp., Cladosporium sp., Xylariales sp., Penicillium sp., Stachybotrys sp., Gibberella moniliformis, Fusarium sp. etc. The similarity of strain 4-13 sequence to the most closely related sequences in GenBank was only 89%. It is concluded that there are diverse fungal symbionts with coral Galaxea fascicularis, which have potential new microorganism resources, deserved for further study.