A 3-phenylthiomethylstyrene derivative having the general formula (1): ##STR1## or salt thereof with a base, when X is hydroxyl group, R.sup.1 is hydrogen atom or R.sup.2 is hydrogen atom, a process for preparing the 3-phenylthiomethylstyrene derivative (1), and an antiallergic agent and a tyrosinekinase inhibiting agent containing the 3-phenylthiomethylstyrene derivative (1) as an effective component. The compound (1) of the present invention is a useful intermediate for preparing various organic compounds, and has excellent antiallergic and tyrosinekinase inhibiting activities.