Nanoscopic CdS particles were encapsulated into microchannels of Engelhard titanosilicates, ETS-4 as well as ETS-10, with the photocatalytically active –Ti–O–Ti– quantum wires in their frameworks. The photocatalytic activities for hydrogen production from water under visible light irradiation (λ>420nm) were investigated in the CdS/ETS system. A stable photocatalytic activity under visible light irradiation was found in an aqueous solution containing Na 2 S and Na 2 SO 3 as electron donors. The results suggest that the encapsulation of CdS in ETS-zeolites is effective for separating charge-carriers photogenerated in CdS and for improving the activity as well as the stability.