The aim of this work was to use the functionalized QDs to investigate the expression and distribution of different carbohydrates on the surface of normal live cells (LO2 cells) and hepatocellular carcinoma cell (HepG2 cells) using fluorescence imaging and flow cytometry,to aid in the early diagnosis of HCC.A method of fluorescence detection for evaluating the expression and distribution of carbohydrates in both normal human livecells (LO2 cells) and hepatocellular carcinoma cells (HepG2 cells) using functionalizedquantum dots (QDs) has been proposed in this study.Water-soluble CdTe QDs with a highQY,good photostability and suitable particle size were synthesized using a two-step method,then the two functionalized QDs were successfully fabricated and covalently conjugated withDatura stramonium agglutinin or Lens culinaris agglutinin lectins using1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride.The optical properties of theQDs and functionalized QDs were characterized by using ultraviolet and fluorescencespectra.The chemical characterization of the QDs was carded out using a Perkin-ElmerFT-IR(Fourier transform infrared spectroscopy) spectrometer.The cytotoxicity of the two freeQDs (QD550 and QD618) and the functionalized QDs(QD550-DSA and QDs618-LCA) wasdetermined using a MTT assay.The bioactivity and stability of the functionalized QDs werecharacterized using agarose gel electrophoresis,hemagglutination activity tests andcarbohydrate inhibition assays.The functionalized QDs were almost homogeneouslyspherical-shapedparticlesandstableforatleast3monthsat4℃C,whichiscrucialforbiolabeling applications.The fabrication process of the functionalized QDs did not decreasethe carbohydrate recognition abilities of lectin and fluorescence intensity of QDsSignificant differences in GalNAc and GlcNAc/Man residue expression and distribution onnormal human live cells and HCC cells were observed.These differences in carbohydrateexpression may serve as potential indicators of cancer detection and treatment.Fluorescencemicroscopy images and flow cytometric analysis results illustrate that the functionalized QDscould be used as tools for the determination of differences in the carbohydrates expressed oncell surfaces.This is very important for understanding the role of carbohydrates in thedevelopment of liver cancer,as well as for the diagnosis ofhepatocellular carcinoma.