Cellulose acetate butyrate (CAB)/poly(butylene succinate) (PBS) blend films were prepared by using a cast blend method with chloroform. Homogenous blend films were obtained over a wide range of the blend ratio. The compatibility and physical properties of the blends have been investigated. The following conclusions were deduced: i) CAB molecules inhibit crystallization of PBS in the blends; ii) over the range of PBS contents from 0 to 30 wt %, PBS molecules have a high miscibility with CAB molecules and PBS molecules are in an amorphous state: iii) over the range of PBS contents from 30 to 80 wt %, PBS molecules form both crystalline and amorphous regions, and a portion of the amorphous PBS molecules is blended with CAB molecules; iv) porous material could be obtained by immersing the blend films in acetone. (C) 2005 Wiley Periodicals, Inc.