Objective To study the fecel-oral and blood transfusion of TT virus. Methods Paired feces and serum samples from 6 patients with type B and/or C hepatitis were tested for TTV DNA and its titers by PCR with seminested primers.Genotypes were determined after their sequences were compared with the original N22 and TA278 clone.Results TTV DNA was detected in sera from all patients,while it was detected in feces from 3 patients,including 2 with high viral titers in serum.The detection of fecal TTV DNA was dependent on the viral titers in serum.TTV isolates in 3 pairs of feces and serum had identical sequence of 222 base pairs.Their genotypes were 1a,1b and 2,respectively.Conclusion The excretion of TTV into feces indicates that TTV would be transmitted not only parenterally but also nonparenterally by a fecal-oral route.