Zinc oxide which is one of the well known materials for photocatalyst, though not so wider than titanium oxide, is cheaper and could be prepared easily through wet process. It is well kown that the zinc oxide dissolves in acidic or alkalic medium. So zinc oxide could be available if the environment is limited to gaseous phase. The purpose of this research is to develop and examine the zinc oxide photocatalyst containing nano particlulate titanium oxide. Thus prepared specimen showed that higher photocatalytic activity than titanium oxide, and photocatalytic activity was observed also under visible light irradiation.