Abstract: Physiological race 2 of Fusarium oxysporum f.sp.conglutinans was used as experimental material.Homologous recombination and PEG mediated protoplast transformation were used to knock out the gene encoding AdoMet-MTases in F.oxysporum.The physiological function of the protein in F.oxysporum was studied by comparing phenotypic differences between wild type and mutants, in order to provide referance for the control of Fusarium wilt.The results showed that the deletion mutants had fewer hyphae,fewer branches,higher sporulation and spore germination rate than the wild-type strain.The mutants were not sensitive to oxygen stress and osmotic stress,and showed a significant increase in pathogenicity on cabbage seedlings.The results suggested that the gene might be involved in regulation of various stresses and maintained homeostasis through negative regulation of growth and development in F.oxysporum.