Abstract: A new technology of extracting salvianolic acid B with high concentration from Salvia mihiorrhiza bunge was developed. The craft of water extraction-chitosan flocculation-fihration-concentrationethanol sedimentation-liquid-liquid extraction with organic solvents was applied to obtain extract EB80, whose content is about 80%. EB80 was purified by column adsorption, extract EB96,whose content of sal- vianolic acid B is 96%, was obtained. IR,MS and ^1H-NMR detection of EB96 shows that the sample has the same structural characteristics and relative molecular moment as those of salvianolic acid B. The technology is convenient to be industrialized.