Apolipoprotein CⅠ,CⅢwere isolated and purified by ultracentrifugation, gel filtration and high performance liquide chromatography from human serum very low density lipoprotein. The purity of apo CⅠ and CⅢ was characterized by IEF、SDS-PAGE and double immunodiffusion. The BALB/C mice were immunized by purified apo CⅠ or CⅢ.4 lines of hybridoma to apo CⅠ and 2 lines of to apo CⅢwhich were able to secreat monoclonal antibOdies(McAb) to human apo CⅠ and apo CⅡ respectively were established. The McAbs have no cross reaction to apo A_Ⅰ,A_Ⅱ,B,CⅡ,E and human albumin.