AbstractBACKGROUNDChinese sturgeon (Acipenser sinensis), a rare species, is an important fishery resource in China. To save this species from overfishing, damming and pollution, artificial propagation has been developed rapidly in recent years. However, the cartilage from Chinese sturgeon, which contains an abundance of chondroitin sulfate (CS), is currently discarded as solid waste after consumption of the fish. The aim of this study was to investigate the extraction, purification and characterisation of CS from Chinese sturgeon cartilage.RESULTSThe optimal extraction parameters were a ratio of aqueous NaOH to cartilage powder of 9.2, a concentration of aqueous NaOH of 4.4% and an extraction time of 3.9 h. Under these optimal conditions the yield of crude CS from Chinese sturgeon cartilage was 26.51%, in agreement with the model prediction (26.54%). Purification by DEAE‐52 cellulose and Sephadex G‐100 column chromatography yielded a single fraction, CS‐11. Its characterisation indicated that CS‐11 was consistent with the polysaccharide backbone structure –4GlcAβ–3GalNβ– and was present in the form of chondroitin‐4‐sulfate and chondroitin‐6‐sulfate.CONCLUSIONThe results of this study provide a basis for promoting the utilisation of Chinese sturgeon resources and are significant for the development and utilisation of CS from Chinese sturgeon cartilage in the food industry.