Abstract: Cellulose polycaprolactone was prepared by grafting of cotton linter pulp with caprolactone(CL)catalyzed by Ti(O-n-Bu)₄ via ring-opening polymerization. Effects of reaction temperature, reaction time, Ti(O-n-Bu)₄ amount, and caprolactone(CL)on monomer conversion and graft rate were investigated through single factor experiments and orthogonal test. The results showed that the significance sequence of the factors affecting the grafting rate was reaction temperature, mass ratio of CL to cellulose, and reaction time. The optimal reaction conditions were as follows: the amount of catalyst was 2%(PCL theory degree of polymerization was 37), the mass ratio of CL to cellulose was 30, and the graft polymerization was carried out at 130 ℃for 25 h. At aforesaid conditions, conversion of CL reached 97.46% and graft rate of cellulose was 70.44%. Structure and properties were characterized by FTIR, ¹H-NMR, XRD. The FTIR result confirmed cellulose has been grafted with PCL. The ¹H-NMR analysis showed that most of the CL had transformed into PCL, and the calculated CL conversion according to ¹H-NMR was consistent with the result of weight measurement method. The XRD results showed that cellulose crystalline structure in cellulose-PCL has decreased, instead crystalline characteristic peaks of PCL was appeared.