During 2009/2010, reddish brown lesions were observed on stems of some mungbean plants grown at the experimental research stations at Nubariya (El-Behera Governorate) and (Beni-Suef Governorate). The pathogen was identified as Colletotrichum dematium. Two isolates varied in morphological and cultural characteristic. Also, they varied in pathogenicity under greenhouse conditions and mycelial growth under laboratory conditions. Culture filtrate of isolates varied in their effect on percentage of seed germination and root length. Isolates varied in their ability to utilize carbon and nitrogen of sources. They also varied in mycelium dry weight and spores production. It was found that mycelial growth and spore production of two isolates was significantly affected by period of light and dark as well as temperatures.