Abstract: A suspected pathogen that caused the stalk rot on Anoectochilus roxburghii was isolated by means of tissue separation.It was subsequently subjected to the pathogenicity tests, morphological observation and molecular biology analysis for positive identification.The massive amount of aerial mycelia of the pathogen were gossypine, separate, branched, and capable of generating apurple pigment.Its macroconidium appeared in the shape of a spindle, and the microconidium in the shape of an egg.By inoculating the isolated strain to A.roxburghii, a pathogenicity to the plant was observed.Based on a blast test of rDNA-ITS sequence, the blight pathogen was identified to be Fusarium oxysporum Schl.