Macromolecules have a strong tendency to interact with each other in solution to form a supramolecular structure through various secondary binding forces. In this study, nucleobase‐containing templates poly(9‐(4‐vinylbenzyl)adenine) (PSAH) and poly(1‐(4‐vinylbenzyl)cytosine) (PSCH) are prepared by reversible addition‐fragmentation chain transfer (RAFT) polymerization. Vinylbenzyl thymine (MST) is polymerized in the presence of these two nucleobase‐containing templates. MST shows higher affinities toward the template PSAH compared with the template PSCH. In accordance with the Watson–Crick pairing principle, thymine forms hydrogen bonding (H‐bonding) with adenine, but not between thymine and cytosine. A complex is formed when PSAH is used as template which indicates that there is a template polymerization of nucleobase complexes via molecular recognition.