AbstractIn a suspension culture ofVinca roseaL. three distinct growth phases were distinguished: a cell division phase, a cell expansion phase, and a stationary phase. At various stages of the growth cycle, extra‐cellular polysaccharides (ECP) and cell wall were isolated and their compositions were investigated. ECP are mainly composed of xyloglucan, 3,6‐linked arabinogalactan, and polyuronide. From the results of gas chromatographic analyses of sugars and partially methylated sugars in each fraction of cell wall polysaccharides, the following changes were observed in the composition of cell wall polysaccharides during culture: (1) a decrease in polyuronide content, (2) a decrease in non‐cellulosic glucan content, (3) an increase in xyloglucan content, and (4) an increase ina‐cellulose content. The significance of the changes is discussed in relation to the growth o