Objective To investigate the changes of Toll-like receptor 4 (TLR4) in the aortas of patients with coronary atherosclerosis and its association with atherosclerotic risk factors. Methods 63 pieces of aorta tissues from 31 patients undergoing coronary artery bypass graft (CABG) surgery were taken as the study group. Another 32 pieces of aorta tissues from 8 healthy young men through the kidney donation program were taken as control. Expression of TLR4 protein was determined by immunohistochemistry. The relationships of TLR4 protein expression and the risk factors of atherosclerosis, including age, gender, smoking, hypertension, hyperglycemia, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total cholesterol(TC) and triglyceride(TG) were analyzed. Results TLR4 protein was detectable in aortas from CABG patients. However, it was absent in the control aorta tissues. Expression of TLR4 protein was correlated with hypertension, hyperglycemia, increased LDL-C and decreased HDL-C (P<0.05), but not correlated with age, gender, smoking, TC and TG (P>0.05). Conclusion Our study demonstrates that the TLR4 protein may be an initiator factor of atherosclerosis. The risk factors including hypertension, hyperglycemia, increased LDL-C and decreased HDL-C which work partly through the TLR4 signal pathway.