Monoclonal antibodies agaist human apolipoprotein E were prepared. Double McAbs Sandwich ELISA has been developed to quantitate apoE concentration in human serum. This paper presents the details of analytic procedure, and the evaluation of its specificity, precison, accuracy and sensitivity. The McAbs reacted specifically with apoE, no cross reaction with apoA Ⅰ、A Ⅱ, B, C Ⅰ , C Ⅱ , C Ⅲ was observed. The assay could detect 10ng of apoE, average recovery was 101.6%, the cofficients of variation of the intra—assay and inter—assay were 5.9% and 8.1%, respectively. The assay was used to quantitate apoE levels in normol persons and patients.