A series of carboxymethyl chitosan samples (CMCHs) with different molecular structural parameters were synthesized to estimate their different influences on the growth of fibroblasts. All the CMCHs stimulated the fibroblasts proliferation and CMCHs with different molecular weight (MW) had the similar effect on fibroblasts proliferation. The least concentration for CMCHs (the degree of deacetylation, DD 70.3-79.9%, the degree of substitution, DS 1.12-1.26) exhibiting acceleratory effect on fibroblasts proliferation was 50 mu g mL(-1). As the DD increased from 70.3 to 93.6%, CMCH's ability of stimulating fibroblasts proliferation increased significantly. CMCH possessed much higher protiferation rate with the DS increasing to 2.39. CM40 with 92.4% DD and 2.39 DS had the strongest acceleratory fibroblasts proliferation at the range tested. (c) 2007 Wiley Periodicals, Inc.