The development of metal-free and water-compatible photocatalysts for visible light-induced environmentally friendly transformation in water is highly desirable. Herein, two types of polyporphyrin based heterogeneous photocatalysts with different water-solubility in water, namely, an insoluble polymer and a water-dispersible nanoparticle, were disclosed. Both of them exhibited excellent photocatalytic activity in visible-light induced functionalization of C(sp3)-H bonds on a wide range of substrates in water. The reusable and recyclable photocatalysts provided a green and sustainable approach for photocatalysis in water.