The characteristics of intensity tuning and polarization of He-Ne laser with optical feedback are studied. When the inteal cavity length of the laser with birefringence optical feedback is tuned, not only does output intensity vary with laser frequency, but also the polarization periodically hops between two orthogonal directions. Ff the phase difference of birefringence is π/2, two polarization states alteately oscillate and have equal bandwidths within the longitudinal mode spacing. The times of polarization flipping in the longitudinal mode bandwidth is proportional to the ratio of exteal cavity length to inteal cavity length. The experimental results are explained, and the potential uses are also discussed.