The use of polymerase chain reaction (PCR) for labeling probe has been demonstrated to offer various advantages including efficient labeling of DNA fragments as small as 72 bp, direct labeling of genomic DNA, and labeling with subnanogram amounts of input DNA. Therefore, a procedure for the nonradioactive labeling of chromasomal DNA 203 bp fragments of Helicobacter pylori with the hapten digoxigenin (Dig) by PCR has been developed. The results showed that the concentration of probe labeled by PCR was much higher than that by random primer labeled. PCR has the advantage of rapidity and economy. It is a very effective technique for synthesis of Dig-labeled DNA probe.