Abstract: Gum rosin derived methacrylate(GRGMA) was firstly synthesized by the esterification reaction between gum rosin(GR) and glycidyl methacrylate(GMA). Subsequently, atom transfer radical polymerization(ATRP) was applied to fabricate ethyl cellulose-gum rosin-fatty acid derived co-polymer(EC-R-LMA). The structure and properties of GRGMA and EC-R-LMA were then characterized by FT-IR, ¹H NMR, DSC, TG/DTG, universal tensile machine and contact angle measurement. It was found that the monomer conversion was higher than 90%. With the increase of the molar ratio of GRGMA from 10% to 70%, the T_g of EC-R-LMA increased from -61.3 ℃ to 62.58 ℃. Particularly, when the molar ratio of GRGMA increased from 30% to 35%, the tensile strength at break increased from 0.41 MPa to 0.50 MPa, whereas the tensile strength at break of the cross-linking polymer(BMI-EC-R-LMA) increased to 1.04 and 1.27 MPa respectively after cross-linking. It was also observed that when the molar ratio of GRGMA and LMA was set to 1∶9 and 2∶8, the T_g of EC-R-LMAs were -61.3 ℃ and -52.9 ℃, respectively, which could be used as a pressure-sensitive adhesive(PSA). Notably, GRGMA acted as a new type of hard monomer for the PSA rather than as a tackifying resin. While the molar content of GRGMA increased from 10% to 20%, the 180° peel strength of PSA increased from 0.56 N/cm to 1.08 N/cm, and the shear resistance property increased from 2 h to more than 72 h.