Summary: We developed a novel method of producing polymer gels in aqueous solution using UV irradiation. Persulfates were effective photosensitive initiators of polymerization and/or gelation of acryloyl‐type monomers/polymers. The gelation was confirmed by an abrupt increase in light scattering intensity, 〈I(q)〉T, at the gelation point. The gelation method entails significant advantages: it does not need any cross‐linkers, temperature control (heating), and additives except the persulfate.