Compression of ultrashort pulses in strongly birefringent optical fibers is studied. When the third order dispersion is considered, one of polarization pulse compression is enhanced and the other polarization pulse compression is suppressed due to the interaction of the third order dispersion and nonlinear effects. Slow soliton is compressed in the fiber with positive third order dispersion, fast soliton is done in the fiber with negative third order dispersion. The large value of third order dispersion parameter, the more evident the compression effect.