Objective To investigate the correlation of serum magnesium level and coronary atherosclerotic heart disease (CHD) and left ventricular function of stage 5 patients with non-dialysis chronic kidney disease (CKD). Methods According to the history of CHD, 43 stage 5 patients with non-dialysis CKD were divided into the CHD group (n=24) and control group (n=19). Basic information, serum magnesium, heart rate (HR), stroke volume (SV), stroke index (SI), cardiac output (CO), cardiac index (CI), pre-ejection period (PEP), left ventricular ejection time (LVET), and PEP/LVET of patients were recorded. The t test and Pearson correlation analysis were conducted by the SPSS 15.0. Results The serum magnesium level, SV, SI, and LVET of the CHD group were lower than those of the control group (P<0.05). The serum magnesium level of the CHD group positively correlated to LVET (r=0.66, P<0.01) and negatively correlated to PEP/LVET (r=－0.38, P<0.05). Conclusion The serum magnesium level of stage 5 patients with non-dialysis CKD and CHD was low and relevant to the left ventricular systolic function.