To efficiently detect and identify a promoter DNA having a DNA sequence of which DNA binding type transfer factor, in which recognition sequence is unknown, specifically recognizes.

This method for detecting a promoter DNA containing recognition sequence of a DNA binding type transfer factor in which recognition sequence is unknown is characterized by simultaneously expressing the following two kinds of genes (a) and (b) in a host: (a) A chimera gene encoding a chimera protein comprising the above transfer factor or DNA binding domain of the above transfer factor and activation site of well-known DNA binding type transfer factor. (b) A selected marker gene having an arbitrary DNA fragment in the upstream and not having own promoter sequence and a part of 5' terminal of a structural gene.