To introduce N-methylmorpholine-N-oxide (NMMO) process to prepare antibacterial lyocell fiber, the blend films of O-carboxymethyl chitosan (O-CMCS) and cellulose were prepared. O-CMCS in aqueous suspension with particles having a surface mean diameter of 2.24 mu m was blended with cellulose in NMMO hydrate. The blend films with different O-CMCS content were prepared with the blend solutions. SEM confirmed that O-CMCS remained within the cellulose film in the particle. The mechanical properties of the blend films show little increased value when O-CMCS was less 5%; however, it decreased sharply when O-CMCS was over 8%. Thus, the optimum O-CMCS content may give a good combination of antibacterial action and mechanical properties. (c) 2006 Wiley Periodicals, Inc.