Emissions from traffic, industrial combustion, heating and biomass burning are important sources for the formation of haze, of which PM2.5 is particularly harmful to human health.Regionally, PM2.5, PM10, CO and SO2 concentrations are generally higher in northern China than in western, southeast and southern China because of large PM emissions and unfavorable meteorological conditions for pollution dispersion.Seasonally high pollutions are often visible in autumn in southeast and western China.Daily, PM2.5 is frequently higher during nighttime than during daytime.The increase in PM2.5 in nighttime can be attributed to heavy vehicles such as diesel trucks, evening recreation activities such as barbecues, and illegal rubbish buming.Of various factors promoting the formation of haze, stagnant airflow is very important because it makes the dispersal of aerosols difficult.This is crucial for the nighttime because the ground temperature decreases during the nighttime and air turbulence decreases leading to very little vertical air motion.Such meteorological conditions had led to Lake Nyos and Bhopal disasters in history.In this ongoing study, we hypothesize that the change of emissions from nighttime to daytime could be a way to lessen haze pollutions in China, and attempt to use public available data to analyze this realization of hypothesis.