Abstract: ObjectiveTo investigate the TTV genoty pes distribution in healthy population of shanghai.MethodsTTV DNA in serum was detected by semi-nested PCR.Partial gene of TTV was sequenced directly from the PCRproducts,and their genetic variation was analyzed.ResultsThere were 21 positive cases in 100 serum samples from healthy population.Fourteen positive samples were sequenced.Sequencing analysis show ed that 96.2%-99.5% of nucleotides were analogous between 10 cases and TA 278,CMR 12,66.2%-67.6% between another 4 cases and the two strains,but 81.9%-84.8% in the 4 cases with TTV G4 strains.The most analogous to the 4 cases in TTV strains reported in China was 61.SEQ,and the analogous rate was 81.9%-84.3%.ConclusionThe prevalance of TTV was high in Shanghai healthy population.TTV G1a was detected as main subg enotype and a subgenotype of TTV G4 new reported in China distributin Shanghai healthy population.