In this article, we briefly described a time-correlated single photon counting (TCSPC) system specifically designed for extracting the optical properties in turbid medium. This system was evaluated by use of two sets of liquid tissue-simulating phantoms containing different concentrations of Intralipid-10% as scatters and India ink as absorbers. With the distribution of times of flight (DTOF) of photons measured by the TCSPC system, some featured parameters, such as the mean time of flight and the variance of DTOF were calculated. Based on these parameters, we developed a simple and fast method to obtain the absorption coefficient μa and reduced scattering coefficient μs' of the turbid medium. Furthermore, the accuracy of the method was validated using the Monte Carlo simulations. It was found that the optical properties could be extracted with this method, which was much faster than the conventional curve-fitting procedure. Our method could be useful in on-line monitoring of optical properties and of the oxygen saturation (SaO2) in forearm muscle.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.