A general expression for the dynamic electrophoretic mobility of a spherical colloidal particle in an oscillating electric field is obtained from the electrokinetic equations derived by Mangelsdorf and White (J, Chem, Sec. Faraday Trans, 88, 3567 (1992)), On the basis of the obtained general mobility expression, accurate simple analytic formulas suitable for numerical calculation are derived for the dynamic electrophoretic mobility and the ratio of dynamic and static mobilities which are applicable for all kappa a (kappa is the Debye-Huckel parameter and a is the particle radius) at zero particle permittivity and low zeta potentials.