Hopf bifurcation and chaotic properties of a simple second order time-delayed system,which includes bifrucation point,bifurcation direction and the stability of bifrucating periodic solutions,are analyzed. We obtain analytically the phase trajectory equations when the delay degenerates. Furthermore,through bifurcation diagram drawn by means of numerical simulation,the route from perioddoubling bifurcation to chaos is reaveled; using single linearly combinating signals and the feedback control method,we achi...