Abstract: Objective To investigate a supersensitive for nucleic acid hybridization assay. Methods Using the two-roung enzyme-amplified action, PCR amplification, Tb chelate and time-resolved detection technology, target PSA DNA was detected. Results The range of the standard curve for detecting target PSA DNA is more than two order of magnitude; the sensitivity was 10pmol/L (0.5fmol/well); the accuracy and the precision was 77%~95% and 12.9%~15.3% respectively when the target PSA DNA was 10,30 and 60pmol/L. Conclusion The method is a supersensitive and new assay technology which has a good prospect of applications.