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Salinity is a major environmental factor and is responsible for the loss of crop production worth billions of dollars every year.A number of strategies have been applied to alleviate the negative effects of salt stress on plant growth,but they were always existed in some disadvantages.Soil-borne Trichoderma strains are versatile beneficial fungi which can stimulate growth and enhance whole-plant resistance to plant pathogens,but no information is available regarding to the strain of T.longibrachiatum T6 enhances tolerance of wheat seedling to NaCl stress.Here we determined the effect of NaCl stress on T.longibrachiatum T6 growth and the role of plant-growth-promoting fungi T.longibrachiatum T6 in wheat seedlings growth and developments under salt stress,and investigated the role of T.longibrachiatum T6 in the resistance to salt stress at physiological levels.The strain of T.longibrachiatum T6 tolerated lower NaCl stress well but differential inhibitory effects were observed with the higher salt treatment.Wheat seedlings were inoculated with the strain of T.longibrachiatum T6 and were compared with non-inoculated control.Shoot height,root length,and shoot and root weights were measured on 15 days old of wheat seedlings grown under 150 mM or in control.A number of colonies were re-isolated from the roots of wheat seedling under salt stress.The relative water content in the leaves and roots,chlorophyll content and root activity were significantly increased,and the accumulation of proline content in leaves was markedly accelerated with the plant growth parameters,but the content of leaf malondialdehyde（MDA） under saline condition was significantly decreased.The antioxidant enzymes-superoxide dismutase（SOD）,peroxidase（POD）,and catalase（CAT） in wheat seedlings were increased by 29,39 and 19%,respectively,with the application of the strain of T.longibrachiatum T6 under salt stress.