To take advantage of cellulose material and prepare a kind of high performance fiber, multi-walled carbon nanotubes (MWNTs) were used as fibers to produce MWNTs/cellulose composite fibers using ionic liquid as solvent. The thermal properties,mechanical properties,and structure of the composite fibers were investigated.The wide angle X-ray diffraction (WAXD) measurements show that MWNTs/cellulose composite fibers have cellulose Ⅱ crystal structure.The results obtained from thermal gravimetric analysis (TGA) indicate that the addition of low nanotubes amounts leads to an increase in the degrade temperature.The tensile mechanical properties show that initial modulus and tensile strength considerably increase in the presence of nanotubes with a maximum for 66.7 ％ and 22.7 ％.