The hydrophobic modification of bagasse cellulose fiber surface by the adsorption of cationic poly latex with core-shell structure prepared via two-step semi-batch emulsion polymerization was conducted in attempt to enhance the interfacial compatibility between hydrophilic fibers and the hydrophobic substrates for various applications. The results of TEM and dynamic light scattering (DLS) analysis indicate that the core-shell latex possesses a broad particles size distribution, which leads to adsorption of the latex onto fiber surface by two-stage equilibrium. The effects of pH and temperatures on the adsorption of latex for cellulose fibers were described, and the amount of adsorption decreases with increased in pH. The results of FT-IR and SEM for modified cellulose fibers prove the latex particles are adsorbed onto the surface of cellulose fibers successfully. In addition, the surface property of the modified cellulose fibers was also investigated via contact angle measurement. The contact angle of cellulose is changed from 0° to 102°, the results show that the cellulose fiber modified with the latex becomes hydrophobic, allowing the as-modified cellulose to be potential reinforcements for biocomposite. Finally, the adsorption mechanism was proposed according to the adsorption process mainly governed by electrostatic interactions, hydrogen bond, π-π stack and chain entanglement.