Low molecular weight Dicarboxylic Acids (DCA's) are ubiquitos and important components of the organic fraction of atmospheric particles. They have been detected in variety of environments in many regions in the world, including urban, rural and remote marine atmospheres. They also have received much attention because of their roles affecting the global climate by involving in the production of cloud condensation nuclei (CCN) and may contribute to the acidity of precipitation. With a low vapour pressures and high water solubility, diacids have an influence on the chemical and physical properties of aerosol.