Classical trajectory calculations are performed for the Penning ionization system He*(2(3)S) + CH3CN --> He(1(1)S) + CH3CN+ + e(-). Anisotropic model potentials of He*(2(3)S) + CH3CN are adopted to calculate the partial ionization cross sections for the ionic states, (X) over tilde 1(2)E, (A) over tilde 1(2)A(1), (B) over tilde 2(2)E, and (C) over tilde 2(2)A(1). Results of the calculations are compared with experimental collision energy dependence of partial ionization cross sections. Analyses of opacity functions indicate the attractive characteristics of the anisotropic interaction potential for the (X) over tilde and (A) over tilde states, the repulsive nature for the (B) over tilde state, and the transition from the attractive to the repulsive features for the (C) over tilde state.