Abstract:Objective: To study the effects of four species of endophytic fungi on the growth and polysaccharide and alkaloid contents of cultured Dendrobium nobile. Method: Each fungal strain was cultured together with D. nobile, and the plant weight as well as the polysaccharide and alkaloid contents were measured. Result: Compared with the control group, Mycena sp.(MF23)was found to decrease the fresh weight of D. nobile by 24.9%(P<0.01). All four species of fungi have no effect on the dry weight of this plant. On the other hand, Epulorhiza sp.(MF18)and MF23 could increase the percent of dry weight of seedlings (P<0.05). Epulorhiza sp.(MF15)and MF24 increased the number of aerial roots by 4.25 times and 4.14 times respectively (P<0.01). MF23 decreased the numbers of basal roots by 46.5%(P<0.01). MF15,MF18,MF23 and MF24 were shown to increase the content of polysacchride by 153.4%,52.1%,18.5% and 76.7%, respectively. MF23 also increased the content of total alkaloid by 18.3%. Conclusion:Endophytic fungi cultured together with D. nobile could affect the growth of this plant; they also increase total alkaloid and polysaccharide contents.