A method for forming a molecularly imprinted polymer biosensor includes: (a) preparing a reaction solution including an imprinting molecule, a functional monomer, an initiator, and a crosslinking agent; (b) disposing the reaction solution in a space between upper and lower substrates each of which is made of a light-transmissible material; (c) disposing on the upper substrate a photomask having a patterned hole; (d) irradiating the reaction solution through the patterned hole of the photomask and the upper substrate so that the reaction solution undergoes polymerization to form a polymer between the upper and lower substrates; (e) removing the upper substrate after the polymer is formed on the lower substrate; and (f) extracting the imprinting molecule from the polymer so that a patterned molecularly imprinted polymer film is formed on the lower substrate.