We experimentally demonstrate the high frequency chaotic dynamics of an erbium-doped fiber ring laser based on the nonlinear Kerr effect. The route to chaos is experimentally observed with the pump current increased when the polarization controller is adjusted to a fixed and appropriate position. The interference among the multiple circulated electromagnetic fields from the erbium-doped fiber ring cavity can exhibit the quasi-period route to chaos, and the interference length is longer than the fiber ring cavity length.