Aim To study the intracellular apoprotein(a) and apoprotein B₁₀₀ levels of three categories of leukocytes in coronary heart disease,and evaluate the effect of intracellular apoproteins on coronary atherosclerosis status. Methods Patients with no coronary stenosis(n=18)and three-vessel coronary artery disease(n=13)validated by angiography were enrolled in this study.Intracellular apoprotein(a) and apoprotein B₁₀₀ concentrations were measured in monocytes,lymphocytes and granulocytes by flow cytometry. Results It was demonstrated that genes of apoprotein(a) and apoprotein B₁₀₀ would not transcript in leukocytes by reverse transcription-polymerase chain reaction(RT-PCR).But apoprotein(a) and apoprotein B₁₀₀ were expressed in all three categories of leukocytes validated by confocal microscopy and flow cytometry.Stenosis patients had a higher levels of intracellular apoprotein B₁₀₀,represented by mean fluorescence intensity(MFI) in monocytes (189±77 vs 41±13,increased 364%,p<0.01), lymphocytes(102±65 vs 16±6,increased 532%,p<0.01) and granulocytes(417±250 vs 183± 88,increased 128%,p<0.05) than no stenosis patients.And the positive percentage of cells containing apoprotein(a) in lymphocytes,monocytes and granulocytes as well as containing apoprotein B₁₀₀ in granulocytes increased in stenosis patients too. Conclusions All categories of leukocytes can carry apoprotein(a) and apoprotein B₁₀₀,and the intracellular concentrations of apoprotein B₁₀₀ had a close correlation with coronary stenosis.