We have prepared a variety of biomolecule-responsive hydrogels by using biomolecular complexes as reversible crosslinking points. This paper describes two types of biomolecule-responsive hydrogels that undergo volume changes in response to target biomolecules, which were prepared using biomolecular complexes such as antigen-antibody complexes and saccharide-lectin complexes. One is a biomolecule-crosslinked hydrogel that can swell in response to a target biomolecule and the other is a biomolecule-imprinted hydrogel that can shrink. The antigen-responsive hydrogels as biomolecule-crosslinked hydrogels swelled in the presence of a target antigen due to the dissociation of antigen-antibody complexes that played a role as reversible crosslinking points. On the other hand, the tumor marker glycoprotein-responsive hydrogels as biomolecule-imprinted hydrogels shrank in response to a target glycoprotein due to the complex formation between ligands (lectin and antibody) and the target molecule (saccharide and peptide chains of glycoprotein). This paper focuses on synthetic strategy of the biomolecule-responsive hydrogels and their responsive behavior for target biomolecules.