The existence of surface plasmon polaritons (SPPs) at the interface between air/metal-dielectric layered systems is demonstrated. Using the transfer matrix method, we calculate the band structure of periodic metal-dielectric layered system and the dispersion relation of SPPs. It is found that we can effectively tune surface modes by varying the thickness of the top metal layer. Moreover, in the presence of static magnetic field, the time reversal symmetry of systems is broken, and nonreciprocal SPPs can be gotten. In particular, such a system can provide a frequency range where one-way SPPs are allowed.