We report on the development of incoherent broadband cavity enhanced absorption spectroscopy system based on a short arc Xenon lamp for trace gas detection and aerosol optical properties measurements. A minimum detection sensitivity of 1.8 10-7cm-1 (1, 0.12 s integrating time, and 50 times average) is obtained on the basis of absorption spectroscopy of NO2 in a spectral range of 520560 nm, which corresponds to a minimum detection concentration of ～33 nmol/mol for NO2. Combining a laboratory aerosol generation system, the extinction coefficients of 600 nm diameter monodispersed ammonium sulfate aerosol are measured under different particle concentrations. A cross-section of 1.12 10-8cm2 for ammonium sulfate at 532 nm wavelength is obtained, which agree well with the literature result of 1.167 10-8cm2. The results demonstrate the ability of our system to quantitativly measure aerosol optical properties.