The electrophoretic behavior of a spherical particle with nonuniform surface potential and that with constant surface charge density along a narrow converging-diverging cylindrical pore were investigated by the finite element method. The effect of double layer polarization was also considered in this study. The key factors we concerned include: the degree of nonuniformity, the double layer thickness, the shape and the charged condition of the boundary. Several interesting results are observed. For instance, we show that the mobility of nonuniform particle is smaller than that of uniform ones. Also, the increase of mobility around the converging-diverging section is also observed in experiment. These phenomena are both fundamental and practical in electrokinetic of colloid.