Abstract: Pathogen of watermenlon wilt disease was isolated and cultured on PDA and PD, which was indentified was Fusarium oxysporum Schlecht by analysis of morphological characteristics and rDNA-ITS sequence and pathogenic determination. The co-toxicity coefficient of 85% oligosaccharins and 97% prochloraz mixed against Fusarium oxysporum were tested in lab by mycelium growth rate method, respectively. The results showed that synergistic inhibition best when 85% oligosaccharins and 97% prochloraz combinations mixed by 3∶1, co-toxicity coefficient was 167.88, obviously inhibitory against the pathogen.

Key words: Fusarium oxysporum, fungicides, combined action, mixture