The present invention relates to a method for analyzing biomolecules by using an oligonucleotide, and specifically, provides a method and an apparatus for determining the meaning of biomolecules in a biosample by analyzing through one examination of the biomolecules contained in the biosample by preparing, with respect to a nucleic acid including a target nucleic acid such as nucleic acid and receptor-analysis ligand conjugates, an oligonucleotide, which complementarily binds completely to a specific region of the target nucleic acid, and analyzing the target nucleic acid.