The unidirectional operation properties of CW ring dye lasers are dicussed. "Using the improved ganiel model of rate equations, the paper analyses the influences of pumping flux and dye molecules density on photon flux, exeited-sbate population density and gain under condition of unidirectional operation.It points out that there are unsymmetry of population density to the position in the medium and correlation between photon flux and position in the medium, and the wavelength of peak gain has the scanning properties. The numerical computation results are given.