It is very difficult to directly spin the lignocellulose without pretreatment. Ionic liquids (ILs) are promising solvent to dissolve lignocellulose to prepare cellulose fiber. However, the degree of cellulose polymerization(DP)is reduced when lignocellulose is dissolved in ILs, and the lignin removal rate is low. The elongation at break and tensile strength of the fibers obtained by spinning the lignocellulose dissolved in ILs are poor. In this paper, preparing cellulose fiber directly from lignocellulose based on dissolving co stalk via [C4mim]Cl-L-arginine binary system is achieved. It shows that the removal rate of lignin can reach 92.35％and the purity of cellulose can reach 85.32％after co stalk was dissolved at 150 ℃C for 11.5 h when the mass fraction of arginine is 2.5％. The elongation at break of fiber reached 10.12％ and the tensile strength reached 420 MPa. It is mainly due to the fact that L-arginine not only inhibits the degradation of cellulose but also promotes the delignination. Without any pulping or pretreatment, preparing cellulose fibers via direct dissolution and extrusion may provide a simple and effective way to prepare many novel cellulose materials.