Abstract: The process of flue gas purification with photocatalytic abatement of nitrogen oxides has become a resource-economical and environment-friendly technology. To develope high-efficient，stable photocatalyst materials plays a crucial role in the photocatalytic process and is the primary step to industrial application. This paper reviews the influencing factors of photocatalytic removal of NOx and addresses the methods to improve catalytic efficiency，based on which，some suggestions are proposed for further study.