Abstract: A bifurcation phenomenon was discovered by experiments in a gas turbine combustor with a non-slat conical swirler.With different kind of perturbation,two different flow patterns may be found in the liner of this gas tubine combustor separately.The characteristics of these two flow patterns are quite different as described in great detail in this paper.In addition,a brief analysis of the causes for initiation of this phenomenon was made on the basis of the experiments.Therefrom it is shown,that this phenomenon will cause flame periodical fluctuation.