Abstract: To solve the problem of environmental pollution and sustainable development issues,a biodegradable composite made from jute fiber and poly butylene succinate(PBS) was prepared by the method of molding,and the effects of fiber contents and alkali treatment on the properties of the composite were researched by mechanical property tests,FT-IR and SEM.The experimental results show that with the increase of jute fiber content,the tensile strength of the composite firstly increases and then decreases,reaching the maximum at the fiber content of 10%,which has increased by 30.1% than that of pure PBS.The tensile modulus,flexural strength and modulus gradually improve,which increase by 24.2%,185.5% and 107.7% respectively than those of pure PBS at the fiber content of 30%.Compared with the surface of jute fiber before alkali treatment,the one after alkali treatment was rougher since it was partly eroded,i.e.,a certain amount of lignin,wax and oils covering on the surface of jute fiber was removed by alkali treatment.So the alkali treatment improves the mechanical property of jute fiber reinforced PBS composites.Especially,the flexural modulus of the composite with alkali treated jute fibers significantly increases by 58% over the untreated jute composite.