Bacterial cellulose has been found to be attractive as a novel scaffold material due to its unique material properties. Porosity is the most important morphological parameter in the design of scaffolds for tissue engineering. The effects of fermentation conditions (cultivation time and inoculation volume) and post-treatment methods (alkali treatment and drying methods) on the porosities of bacterial cellulose membranes were investigated. With extended cultivation time and increased inoculation volume, more micro-fibrils were secreted by bacteria, which resulted in a more compact structure and diminished porosity. The porosities of alkali-treated bacterial cellulose membranes was in the order of K 2 CO 3 [ Na 2 CO 3 [ KOH [ NaOH. Freeze-dried membranes had much higher porosity (92%) than the hot air-dried ones (65%). The experimental results suggested that bacterial cellulose with controlled porosities could be prepared by varying fermentation conditions and post-treatment methods. The resulting bacterial cellulose is regarded as a scaffold material of great potentialities.