Objective To investigate variation of serum homocysteine in middle-aged and elderly population. Methods The serum Hcy were detected in 446 middle-aged and elderly persons and analyzed by gender and ages. The changes of serum Hcy in persons with hypertension, coronary heart disease (CHD) and cerebral apoplexy were studied. Results The mean value of serum homocysteine was 16.60±7.58µmol/L. A higher homocysteine in male and persons more than 80 years were observed. The serum homocysteine in persons with cardio-cerebral vascular disease were higher than that of normal control. Conclusion There are gender and age difference in serum homocysteine. The hyperhomocysteinemia (HHcy) is a risk factor for cardiac-cerebral vascular disease.