For the p polarizations, the surface plasmon polaritons (SPPs) of form birefringence metal and regular materials are investigated. According to the biaxial anisotropy of the permittivity of the form birefringence metal and the dispersion relations of SPP, the characteristic lengths of SPP, including SPP wavelength, propagation distance of SPP and penetration depths of SPP in two media, are discussed in X direction and Y direction. In addition, the effects of three periodic structure parameters of form birefringence metal on the characteristic lengths of SPP are discussed. It is shown that the structure period in Y direction only controls the characteristic lengths of SPP in X direction, the structure period in X direction only affects the characteristic lengths of SPP in Y direction, and the radius of nanoholes adjusts the characteristic lengths of SPP in both X direction and Y direction.