Elemental carbon (EC) aerosol represents an important fraction of aerosol particles in urban area of the Pearl River Delta (PRD) region, China. Previous studies have demonstrated that EC particles in the PRD region undergo significant amounts of aging processes. To assess the degree of aging, the real-time single particle volatility of EC-containing particles was measured in an urban area of the PRD region by a thermodiluter coupled to a single particle aerosol mass spectrometer (SPAMS). The size and chemical composition of the individual particles before and after heating to 75 degrees C, 150 degrees C and 300 degrees C were characterized. Of the total unheated particles examined by SPAMS, 53% of the unheated particles contained EC, and a higher number fraction (69%) was observed in the particles heated to 300 degrees C. No significant differences in the mass spectral patterns were found between ambient temperature and 75 degrees C. Nitrate evaporated at 150 degrees C, and most of sulfate evaporated at 300 degrees C. EC-containing particles were clustered into four distinct particle types based on the dominant chemical species present in the mass spectra, comprised of EC, internally mixed EC and organic carbon (OC) (ECOC), internally mixed EC and sodium/potassium salt (NaK-EC), and internally mixed EC and metal species (Metal-EC). Detail analysis show that the volatility of EC-containing particles relied on the EC particle types. Among the four types, the EC type was quite volatile. A significant fraction of sulfate and organics in the ECOC type did not volatilize at 300 degrees C. The volatilities of secondary ions in the four EC-containing particle types were found to be dependent on their molecular composition. Additionally, the volatility of EC-containing particles decreased during the polluted hazy days due to the generation of low volatile compounds under the atmospheric conditions with higher precursor concentrations and oxidation capacity. To our knowledge, this is the first reported real-time volatility measurements of individual ambient aerosols in the PRD region. These findings provide an improved understanding of the aging process of EC particles, and may help in the modeling of its climate impact. (C) 2015 Elsevier Ltd. All rights reserved.