ALM To determine the frequencies of HGV and TTVinfections in blood donors in Hangzhou.METHODS RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection in the sera from 203 blood donors, and nucleotide sequence analysis were performed.``RESULTS Thirty-two ( 15.8%) and 30 (14.8%) of the 203serum samples were positive for HGV RNA and TTV DNA,respectively. And 5 (2.5%) of the 203 serum samples were detectable for both HGV RNA and TTV DNA.Homology of the nucleotide sequences of HGV RT-nested PCR products and TTV semi-nested PCR products from 3serum samples compared with the reported HGV and TTV sequences was 89.36%. 87.94%, 88.65% and 63.51%.65.77% and 67.12%. respectively.``CONCLUSION The infection rates of HGV and/or TTV inblood donors are relatively high. and to establish HGV and TTV examinations to screen blood donors is needed for transfusion security. The genomic heterogeneity of TTV or HGV is present in the isolates from different areas.``