The present invention discloses an oxidized mixed cyclic phenol sulfide which is a mixture of the oxidized cyclic phenol sulfide wherein m is 8 and the oxidized cyclic phenol sulfide wherein m is an integer other than 8, the oxidized cyclic phenol sulfide being represented by the following formula (1): ##STR00001## wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, m is an integer from 4 to 9, and n is 1 or 2; or an oxidized cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.