Under the initiation of benzoyl peroxide or ultraviolet light,thiophenol added smoothly to 1-phenylpropyne-1 and to 1-phenylbutyne-1.When equimolecular ratio of the reactants was used,the addition products were 1-phenyl-2-phenylthiopropene-1 (Ⅰ) and 1-phenyl-2-phenylthiobutene-1 (Ⅱ),respectively.When the amount of thiophenol used was doubled,there were obtained,besides the one-to-one adducts named,two-to-one adducts; 1-phenyl-2,2-di-(phenylthio)-propane (V) and 1-phenyl-2,2-di-(phenylthio)-butane (Vr),respectively.