A Cu-catalyzed C(sp2)-P bond formation reaction using the acylphosphine as the phosphorus source was reported. With CuCl2 as the catalyst, 34 examples of aryl iodides and bromides were converted to triarylphosphines in good to excellent yield. A preliminary study of mechanism was carried out and denied the existence of a radical intermediate. This reaction was an extension of the acylphosphine’s application into Cu-catalyzed reactions, and indicated its potential application as a phosphination reagent in the synthesis of tertiary phosphines.