【Objectives】 To investigate the detection rate of HCVcAg in patients co-infected with HBV and HCV

and then to analyze the influence factors. 【Methods】 HCVcAg and HCV RNA in sera were detected in 88 patients with chronic hepatitis C and 62 patients who were co-infected with HCV and HBV. At the same time

HBV DNA and HBeAg in sera were detected in 62 patients infected with HCV and HBV. Then we analyzed the correlation between HCVcAg and HBeAg / HBV DNA.【Results】 The detection rates of HCVcAg in 88 patients with chronic hepatitis C and 62 patients co-infected with HCV and HBV were 72.7% (64/88) and 38.7% (24/62)

respectively ( χ= 17.358

P < 0.001). The detection rates of HCV RNA in 88 patients with chronic hepatitis C and 62 patients co-infected with HCV and HBV were 81.8% (72/88) and 53.2% (33/62)

respectively (χ= 20.11

P < 0.001). In 62 patients infected with HCV and HBV

the detection rates of HCVcAg in HBeAg positive patients and HBeAg negative patients were 28.6% (12/42) and 60% (12/20)

respectively (χ= 5.641

P = 0.011). Moreover

the positive rates of HBV DNA in HBeAg positive patients and HBeAg negative patients were 42.9% (18/42) and 80% (16/20)

respectively (χ = 15.452

P < 0.001). The detection rates of HCVcAg in HBV DNA positive patients and HBV DNA negative patients were 39.1% (18/46) and 37.5% (6/16)

respectively (χ = 0.013

P = 0.908). Compared with the detection rate of HCVcAg in patients only infected with HCV

the detection rates of HCVcAg in HBeAg or HBV DNA negative patients infected with HCV and HBV were 60% (12/20)(χ = 1.266

P = 0.261) and 37.5% (6/16)( χ= 7.635

P < 0.01)

respectively. 【Conclusions】 The detection rate of HCVcAg in patients infected with HCV and HBV is relatively low. The reason is possibly that HBeAg inhibits duplication of HCV and decreases the expression of HCVcAg.