Due to the rapid urbanization and industrialization, and excessive consumption of fossil fuel, haze weather characterized by PM2.5 has become a severe pollution problem in major Chinese cities recently, which has harmful effect on the air quality, visibility, clime system and human health. To indicate suitable directions for the prevention and control of haze pollution, the pollutant source apportionment and formation mechanism of urban haze should be figured out firstly. In this work, we briefly review the frequently-used methods for PM2.5 source apportionment and formation mechanism analysis of urban haze based on normal perspective in recent years. Furthermore, based on the new perspective of systematic methodology, the utilization of fault tree approach for the causation mechanism analysis of urban haze is significantly introduced and discussed. Finally, the recent progress on controlling strategies of urban haze in China is also synoptically introduced and discussed. It is expected that more effective tool/method can be found, developed and employed for the causation mechanism analysis and risk management of urban haze in China. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.