The plasma anomalous transport caused by particles transverse drift in a system has been completed, in which the magnetic surfaces are disrupted by a stochastic perturbation of magnetic field. In ergodic region the motion equation can be written in Langevin equation and diffusion coefficient D perpendicular can be obtained from Fokker-Planck model. Comparing with another diffusion coefficient D perpendicular derived by the diffusion of field lines in the quasilinear approximation, the D perpendicular obtained from Fokker-Planck model has the similar form and same order of magnitude. The two D perpendicular `s are supplement to each other. Only when they are combined into one, will the result be completed.