Aim To investigate the effects of C-reactive protein (CRP) on expression of matrix metalloproteinase-2 (MMP-2) in U937 cells and the influence of CRP on matrix remodeling in atherogenesis and plaque rapture. Methods U937 cells were cultured in vitro and intervened by different concentrations of recombination human CRP and provastatin [a: control; b: CRP 5 mg/L; c: CRP 20 mg/L; d: CRP 100 mg/L;e: CRP 20 mg/L+provastatin 10 -3 mol/L]. The MMP-2 mRNA was determined by reverse transcriptase-polymerase chain reaction (RT- PCR) and MMP-2 protein was measured by Western blotting. Results In comparison with the control, the expression of mRNA and protein of MMP-2 significantly increased in 5 mg/L, 20 mg/L and 100 mg/L CRP groups (p<0.05), and this up-regulation of the expression of MMP-2 could be inhibited in CRP 20 mg/L+Provastatin 10 -3 mol/L group. Conclusions CRP can enhance the expression of MMP-2 in U937 cells and may cause advanced inflammation in atherosclerosis plaques. It may provide an explanation for the phenomenon that patients who have high concentration of CRP are prone to have atherosclerotic lesions and plaque rapture.