Abstract: Objective To compare the expressions of lymphocyte and it's subgroups, humoral immune function and liver function between the hepatitis B patients co-infected with hepatitis E virus and the patients of hepatitis E. Methods Totally 78 hepatitis B patients co-infected with hepatitis E virus (including 33 HBeAg positive patients and 45 HBeAg negative patients) and 51 hepatitis E patients were selected and compare their levels of LC, CD3, CD4, CD8, natural kill cell (NK), B cell (BC), Ig G/A/M, ALT, TBIL and PT measured by blood cell analyzer, flow cytometry, immunoturbidimetry, biochemical analyzer and coagulometer respectively. Results There were differences on the levels of CD8, NK between HBeAg positive group and hepatitis E group, on the level of LC, CD3, CD4 and NK between HBeAg negative group and hepatitis E group and on the level of LC, CD3 and CD4 between HBeAg positive group and HBeAg negative group. The difference on the level of IgM was only found between HBeAg positive group and hepatitis E group and between HBeAg positive group and HBeAg negative group. There were differences on the levels of ALT and TBIL between HBeAg positive group and hepatitis E group and between HBeAg negative group and hepatitis E group, and there was difference on the level of ALT between HBeAg positive group and HBeAg negative group Conclusion Co-infection of two hepatitis viruses might cause some interference and might relieve the damage of liver.