Possible operating points of first and higher order polarization mode dispersion(PMD) compensators were presented in both small and large PMD conditions according to the theoretical analysis of the relationship between the PMD vectors of compensating and compensated fibers in Stokes space.Outage probability was used to evaluate the performance of compensating systems.Numerical results show that the optimal performance obtained by the compensators running in these operating points is consistent with what can be acquired by the compensators used in practice.