Bacterial cellulose is a potential biomaterial that can be used in several medical aspects. We have modified bacterial cellulose with alginate to enhance the tear resistance to sewing procedure when used as mucosal flap in oral tissue regeneration. Objectives: To investigate the growth of human keratinocytes (HaCat) and gingival fibroblasts (GF) on alginate modified bacterial cellulose. Methods: Cytotoxicity test was performed in L-929 mouse fibroblasts. Growth and spreading of HaCat and GF on each material were compared and analyzed by MTT and scanning electron microscopy. Results: No toxicity of the material was observed. Unmodified cellulose, but not alginate, supported growth and spreading of HaCat and GF. However modified bacterial cellulose could support only HaCat. Conclusions: Biocompatibility of modified cellulose to keratinocytes in combination with good tear resistance property suggests that modified bacterial cellulose has a good potential to be used in the oral cavity to cover the surgical wound. This study was supported by Ratchadapisek Somphot Endowment, Chulalongkorn University 2006.