Objectives This paper is to investigate the correlation between plasma total homocysteine (tHcy) and coronary artery disease(CAD).Methods Using high performance liquid chromatograph to determine the level of plasma tHcy in 215 cases, and they were selective coronary angiography.107 cases were determined to have CAD with at least one vessel was narrowed ＜ 50%. 108 cases were nonnarrowed, and they were listed as controls. Their 10 parameters such as sex, age, body height, body weight and blood lipid etc. were no statistical difference between two groups. Results The plasma tHcy 11.20(±5.56) μmol/L of the CAD group and 11.46(±5.50) of the control group, between them there was no statistical difference (P ＞ 0.5). 12.17 (±6.25) μmol/L tHcy concentration of the male was significant higher than 9.60(±5.10) of the female (P ＜ 0.001). Conclusions None of correlation between the plasma tHcy and CAD can be found, and the tHcy of male is higher than that of female.