The serum manganese, chromium, zinc and copper levels of 63 cases with coronary heart disease and 33 normals were determined by the inductively couple plasma emission spectroscopy. The concentrations of Mn, Cr, Zn and Cu were 0.02145 ?0.0107 ppm, 0.0230 ?0.0167 PPm, 0.905?0.278 ppm 1.056 ?0.404 PPm and the Cu/Zn ratio was 0.973 ?0.395 in normals.In comparing with normals, a significant increase in the serum zinc concentration (P