Abstract: In April 2020,a serious fruit rot occurred in a passion fruit（Passiflora edulis）planting area in Yulin,Guangxi,with an incidence of about 20%,which seriously affected the yield and quality of fruit.In order to identify the pathogen of fruit rot,three strains were obtained by tissue isolation and identified by pathogenicity,morphological and molecular biological characteristics.The results of pathogenicity test showed that all the isolated strains could cause fruit rot of P.edulis,and the symptoms were similar to those of the field.The characteristics of colony and conidia of the strains were consistent with those of the description of Alternaria alternata.The sequences of the ITS showed 100% similarity to the type strain CBS 479.90（A.alternata）.Therefore,the pathogen of passion fruit rot was identified as A.alternata.This is the first report of A.alternatacausing passion fruit rot in Yulin,Guangxi.