Objective: To study the modification process of carboxymethylated Camellia Oleifera seed meal polysaccharide （CM-COP） and acetylated Camellia Oleifera seed meal polysaccharide （Ac-COP）, and to study their inhibitory effects on hyaluronidase. Methods: Using the degree of substitution as an index, the carboxymethylation and acetylation modification of Camellia Oleifera seed meal polysaccharide （COP） were carried out by sodium hydroxide-chloroacetic acid method and acetic anhydride method, respectively. Results: The best modification process for CM-COP was: sodium hydroxide concentration of 1.5 mol/L, reaction time of 3 h, reaction temperature of 60 ℃; Ac-COP best modification process is: acetic anhydride dosage 3.0 mL, reaction time 3 h, The reaction temperature was 60 ℃; and the inhibition rates of COP, CM-COP, and Ac-COP to hyaluronidase were 78.0%, 90.3% and 92.2%, respectively. Conclusion: COP, CM-COP, and Ac-COP all have inhibitory effects on hyaluronidase, and the inhibitory activities of CM-COP and Ac-COP are higher than COP, indicating that the modification can increase the biological activity of COP.