Abstract: Objective To develop liquid chip-based method for assaying alpha fetoprotein（AFP）in human serum and to evaluate method performance． Methods Different amounts of anti-AFP monoclonal antibody were coupled to fluorescent beads using liquid chip technology in a sandwich immunoassay format. Fluorescent microspheres prepared with the optimal amount of anti-AFP antibody were reacted with different concentrations of biotin-goat anti-mouse IgG，and several performance indicators were measured，including linear range，detection limit，and accuracy.The method was used to measure serum AFP concentration in 134 patients with hepatocellular carcinoma（HCC） and 47 healthy controls，and the results were compared with those obtained by electrochemoluminescence immunoassay（ECLIA）. Results Optimal coupling was obtained with 8 μg of anti-AFP monoclonal antibody and 4 μg/ml of biotin-goat anti-mouse IgG.The linear response range for the method to detect serum AFP was 1.31~168 ng/ml and the detection limit was 0.424 ng/ml. Intra- and inter-assay coefficients of variation ranged，respectively，from 4.33% to 7.66% and from 9.82% to 13.85%.The method detected significantly diffe-rent serum AFP levels between patients with HCC and healthy controls（P<0.05）.Method sensitivity was 85.82% and specificity was 95.74%.Measurements obtained by the liquid chip method showed a correlation coefficient（r） of 0.845（P<0.05） with measurements obtained by ECLIA. Conclusion The liquid chip and ECLIA methods showed good correlation in detecting AFP.Since the liquid chip method offers a wider detection range and greater sensitivity than ECLIA，in addition to showing good repeatability，it may allow faster detection with fewer samples.This approach may also prove useful for detecting AFP together with other multiplexing markers in HCC.

Key words: Liquid chip, Tumor marker, AFP, Method