Abstract: In order to explore the effect of carboxymethylation on Rosa sterilis pomace dietary fiber, the soluble dietary fiber (RSDF) and insoluble dietary fiber (RIDF) of Rosa sterilis pomace were modified by carboxymethylation in this paper. And the physicochemical, functional properties of carboxymethylated total dietary fiber and after the carboxymethylation modification of Rosa sterilis pomace dietary fiber were compared and analyzed. The results showed that after modification, the swelling capacity, water holding capacity, oil holding capacity, moisture absorption, cation exchange capacity, nitrite adsorption capacity and glucose adsorption capacity of CSDF and CIDF increased significantly (P<0.05). When the degree of substitution was 0.53±0.02, the mixing ratio of CSDF/CIDF was 1:3. The optimum mixture ratio was obtained by combining physicochemical and functional properties. FTIR analysis showed that the carboxymethylation of CSDF and CIDF was successful. SEM analysis showed that CSDF and CIDF loose structures, there were more holes and flake structures when the CSDF/CIDF mixing ratio was 1:3. DSC analysis showed that the storage stability of CSDF and CIDF improved after modification. When the mixing ratio of CSDF/CIDF was 1:3, the maximum hot melting temperature was 145 ℃. In summary, after carboxymethylation, the properties of Rosa sterilis dietary fiber were better than before and after integrating various performances, the best CTDF mixing ratio was 1:3.