In recent years, the OTDR-based method has become a familiar technique for measuring chromatic dispersion distribution along an optical-fiber transmission system. In this paper, a nondestructive measurement technique is presented. This technique uses a four-wavelength bidirectional optical time domain reflectometer (OTDR) to measure the chromatic dispersion distribution along an optical-fiber transmission system. A new formulation has been developed to enhance the correction factor, which leads to an improved and precise measurement. The obtained experimental results are in good agreement with those obtained by the interferometric technique.