Socio-economic status and serum lipids are important factors in the progression of cardiovascular disease. We studied the association between socio-economic status and serum lipids in a Chinese urban population. In all, 4,541 respondents (2,231 men and 2,310 women) between 25-64 years of age participated in a cross-sectional population survey carried out in Tianjin, China, and provided blood samples. Three socio-economic indicators (education, occupation, and income), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were determined. People in higher socio-economic groups had a more unfavorable serum lipid profile compared with those in lower socio-economic groups. This significant association was especially apparent in men. Education seemed to be the most important predictor of serum lipids in the three socio-economic indicators. The direction of the association between high socio-economic status and poor serum lipid profiles appears to be opposite to those observed in the developed countries.