Abstract: The grafted block copolymers, ethyl cellulose-g-lauryl methacrylate-b-tetrahydrofurfuryl methacrylate(EC-g-P(LMA-b-THFMA)) was successfully prepared via "grafting from" atom transfer radical polymerization(ATRP) through two-step polymerization strategy. Thermal property analysis showed that this copolymer had two thermal transitions(-35 ℃ and 49-56 ℃), indicating of the presence of microphase separation in the copolymer. Mechanical property analysis showed that the copolymer had excellent thermoplastic elastomer behavior with the elongation of 89%-147% and tensile strength of 1.7-9.5 MPa. The cycilic tensile mechanical properties analysis indicated that the elastic recovery of EC-g-P(LMA-b-THFMA200) was more than 92%. Compared with the linear block polymer P(LMA-b-THFMA), it could be found that the introduction of cellulose significantly enhanced the mechanical properties of graft copolymer. The mechanical strength of graft copolymer was increased by 1.36 times while compared with that of P(LMA-b-THFMA).