Abstract: Psidium stem canker disease was serious yearly in the orchards of guava in the suburban dis-tricts of Guangzhou since 1988.It was proved as a fungous disease and the causal organismwas Botryosphaeria rhodina(Cke.)v.Arx,anamoph:Botryodiplodia theobromae Pat.Thefungus caused stem canker and longitudinal crack on trunks and twigs,and caused fruitsrotted.Both telemorph and anamorph of the pathogen could produee on the diseasedtrunks,twigs and fruits.According to the investigation in 1994,the pereent age ofdiseased trees grown above 4 years-old was over 70%,and many died in those of 6years-old.The test also showed that the fungus did not infect the trunk of Litchi,Mango,Longan,Orange,Chinese wampee,Papaya and Sapodilla and did not infect thecorm of Taro,but could cause fruit-rotted in tropical and subtropical fruit crops.