Aim To compare the functional difference of endothelial progenitor cells （EPC） of high concentration Lp（a） （≥300 mg/L） coronary artery disease （HLPCAD） patients and low concentration Lp（a） （＜300 mg/L） coronary artery disease （LLPCAD） patients. Methods Differential adherence method was used to isolate EPC, Dil-ac-LDL swallowed and lectin binding was used for EPC identification. MTT was used to assay EPC survival and proliferation, modified Boyden chamber for migration, gelatin slide method for adhesion, a single cell hybridoma clones dish was observed and counted, and tubular structures formed on matrigel matrix length was measured. Results The numbers of circulating EPC in HLPCAD patients were significantly lower than those in LLPCAD patients （109.4±13.8 Cells/field vs.384.0±37.0 Cells/field, P0.0023）. MTT analysis showed that the OD value of LLPCAD group was 0.77±0.05, and the HLPCAD was 0.23±0.04 （P0.0018）, the apoptosis rate of HLPCAD EPC was significantly higher than that in LLPCAD group （14.9%±3.3% vs.4.1%±0.8%, P0.035）. The numbers of adhesion （25.3±4.6 Cells/field vs. 78.6 ± 6.8 Cells/field, P0.0030）, migration （22.0±2.6 Cells/field vs. 56.0 ± 4.9 Cells/field, P0.0037）, and clone-form units （2.4±0.4 number/field vs.11.0±1.3 number/field, P0.0003）, tubular structure formation （7.4±1.2 mm/field vs.33.3±2.6 mm/field, P0.0001） of HLPCAD patients were significantly reduced. Conclusions Function of HLPCAD EPC is seriously impaired while compared with LLPCAD EPC.