Abstract: It investigated infectious rate of transfusion transmitted virus (TTV) among the patients with different types of viral hepatitis and blood donor.A semi nested polymerase chain reactions (nPCR) assay was usedwith specific primers from TTV genome.20 cases of sporadic NA NG hepatitis (NA NG H) , 40 cases of fulminate hepatitis (FH) , 20 case of chronic hepatitis B (CHB) , 20 cases of chronic hepatitis C (CHC) and 50 cases of voluntry blood donor (BD) were examined by nPCR.PCR product of two samples was sequenced with Sequencher ABI PRISM) .Positive rates of TTV DNA in NA NG H, FH, CHB, CHC and BD were 5%, 22.5%, 25%, 15% and 0%, respectively.The partial sequence of TTV isolated in Liaoning (SYS 04 & 05) shown 98% above nucleotide identity over the corresponding region of TTV in Japan by Nishizawa.The results shown that positive rates of TTV DNA were the same in FH as CHB, and a superinfection was close relation to developed into severe or persistent disease.It was sure that a blood come from some voluntry donors was safe from TTv infection, when voluntry blood donors were detected normal of all liver function.