Abstract： Objective To conduct a methodological evaluation on flowcytomotry fluorescence detection of serum CA242, and to evaluate its value in the diagnosis of pancreatic cancer.Methods The blood samples of 40 cases of pancreatic cancer, 49 cases of other tumors, 48 cases of benign digestive diseases and 159 healthy volunteers were collected.Fowcytometry fluorescence immunoassay was used to detect serum level of CA242, and it was compared with routine ELISA method to measure its sensitivity and specificity.Results The detection limit of CA242 by flowcytometry fluorescence immunoassay was 0.89 U/ml, the linear range was 1～ 500 U/ml after confirmation.The within-batch CV was 3.37％～ 5.30％, between batch CV was 7.43％ ～ 9.60％.When compared with routine ELISA, flowcytometry fluorescence immunoassay showed the equation of linear regression is Y =1.0398X-0.947, r =0.9687.Area under ROC curve was 0.811 ± 0.025 (95％ CI 0.763 ～0.859), with 18.625 U/ml as the best cutoff value, the specificity was 92.0％ and the sensitivity was 62.1％.Conclusions Flowcytometry fluorescence immunoassay for CA242 testing has the advantage of shorter detection time, miltiple sample and testing project detection, which is worth of clinical application.