A severe particulate pollution event occurred in Chongqing, China beginning on 24th Dec 2014.The highest PM2.5 concentration were 238 μg m-3, black carbon, and 18 μg m-3 at 4th Jan 2015.A Single Particle Mass Spectrometer (SPAMS) was deployed for high temporal trend observation during the pollution event.The ART-2a clustering results suggest that Biomass Burning (BB), BB-aged, and Potassium-rich Elemental-Carbon (K-EC) were major particle clusters, accounting for 82% of total SPAMS particle count.