Viruses present in the blood or blood products serve important infection source to transfusion patients or users of blood products. Human parvovirus B19 has been recognized as a new viral pathogen in human mainly transmitted via blood. Thus, detection of human parvovirus B19 has become an urgent problem to be solved. This study was intended to develop methods to detect human parvovirus B19 in the blood or blood products by nucleic acid amplification technique (NAT) or polymerase chain reaction (PCR). Five sets of primer DNAs were tested for the detection of human parvovirus B19 by PCR. A primer set amplifying 258 nucleotides corresponding Vp1 gene of human parvovirus B19 was chosen and further studies were done to determine the optimum condition to detect human parvovirus B 19 from human blood or blood products. PCR detection of human parvovirus B19 was almost 1,000 times more sensitive than the receptor-mediated hemagglutination assay developed by the Japanese Red Cross Center. Although direct PCR of B19 virus without DNA extraction could detect B19 virus from PBS buffer, attempts to detect the virus from whole blood or plasma failed. PCR after DNA extraction from blood or plasma samples could detect B19 virus as little as $10^4;PFU/ml$. Our results can further be applied for developing routine methods to identify human parvovirus B19 in human blood or commercial blood products.