In order to explore the pathogen causing postharvest fruit rot of yellow passion fruit in Fujian prov-ince and its biological characteristics,the pathogen was isolated from fruit.Its pathogenicity was measured by Koch's postulates,and the pathogenic morphological characteristics were observed.The pathogen was identi-fied by homology and phylogenetic analysis combined with molecular biological identification.Influences of dif-ferent temperature,pH value,carbon source and nitrogen source on the mycelia growth of fruit rot pathogen were preliminarily studied.Results showed that,according to the morphological and phylogenetic identifica-tion,the pathogen causing fruit rot of yellow passion fruit in Fujian Province was Lasiodiplodia theobromae.Moreover,the optimum temperature,pH value,carbon source and nitrogen source for the hyphal growth of L.theobromae were 28 ℃,pH 6,glucose and potassium nitrate,respectively.