With the preparing of SO2+((X) over tilde (2)A(1)(000)) by [3+1] multiphoton ionization of the neutral SO2 molecules at 380.85 nm, the photodissociation process and the symmetry of the excited states (D) over tilde of SO2+ molecular ions has been investigated by measuring the photofragment SO+ excitation (PHOFEX) spectrum in ultraviolet (282-332 nm) and in visible (562-664 nm) wavelength ranges, respectively. The (D) over tilde (v(1)00), (D) over tilde (0v(2)0)<--<(X)over tilde> (2)A(1)(000) transitions of SO2+ were assigned in the PHOFEX spectrum in the UV range. By comparing the discernible PHOFEX spectrum in UV range with the continuous PHOFEX spectrum in visible range, it is deduced that (i) around SO2+((D) over tilde) there exists a repulsive state alpha (2)A(2) converging to the dissociation limit of SO+(X (2)Pi)+O(P-3(g)), (ii) the coupling between SO2+((D) over tilde) and SO2+(alpha (2)A(2)) leads to the dissociation to SO+(X (2)Pi)+O(P-3(g)), (iii) the symmetry of (D) over tilde state is (D) over tilde B-2(1). (C) 2003 American Institute of Physics.