Abstract: More than ten years have passed, since Chinese "vancomycin" was produced by North China Pharmaceutical Corporation. Comparing with typical vancomycin, however, Chinese "vancomycin" shows some differences in antibacterial activity and chromatographic behaviour. Based on the data of nuclear magnetic resonance (¹HNMR and ¹³CNMR), fast atom bombardment mass spectrum and its hydrolyzed products, it was confirmed that there is a leucine rather than a N-methyl-leucine in the molecule of Chinese "vancomycin", but all of the other residues are the same as that of vancomycin. Consequently, Chinese "vancomycin" is actually N-demethylvancomycin.