In our study, 50 patients with dilated cardiomyopathy (DCM) were selected to investigate the correlation between virus persistent infection and cardic function. We found that 44% of patients with DCM were coxsackie virus B-RNA (CVB-RNA) positive, significantly different from that (20%) of the normal control group (P<0.05). The expression levels of coxsackie adenovirus receptor (CAR) in patients with DCM were significantly higher than those in the normal control group (P<0.01). In CVB-RNA-positive patients, expression levels of CAR were significantly higher than those in CVB-RNA-negative patients (P<0.01). There was a positive correlation between CAR expression and brain natriuretic peptide (BNP) level in patients with DCM, but no significant correlations between the CAR expression level and left ventricular ejection fraction (LVEF) or left ventricular end diastolic diameter (LVEDd). These results showed that expression levels of CAR on the surface of white cells can be used as an indicator for detecting persistent virus infection. We found that expression levels of CAR and heart function in patients with DCM were highly correlated.