The present invention relates to a method of detecting and quantifying biomolecules using nucleic acid polymerase activity controlled by the target molecule, and more particularly to a method for detecting or quantifying biomolecules, which can detect and quantify nucleic acids, proteins, small-molecular substances, physiologically active substances (enzymatic activities), etc., with high sensitivity, based on the change in DNA polymerase activity caused by specific binding of a specific nucleic acid that forms a complex with a DNA aptamer prepared so as to comprise a single-stranded DNA that specifically recognizes the specific nucleic acid. The present invention can provide a method for diagnosing biomolecules, which can detect and quantify target nucleic acids, target proteins, target small-molecular substances, target enzyme activities and the like in a label-free and sensitive manner by controlling polymerase activity through target molecule-induced conformational change of a DNA aptamer.