PURPOSE: To obtain a new triphenylalkene derivative useful as a medicine having ulcer-suppressing action being more excellent than that of tamoxifen on breast ulcer.

CONSTITUTION: A compound expressed by formula I (R1 and R3 are lower alkyl or lower cycloalkyl; R2 is H, OH, R4COO, R5OCH2O or OPO(OH)2; R4 is lower alkyl, lower cycloalkyl or substituted aryl; R5 is lower alkyl or lower alkylcarbonyl; Ar is phenyl or 3,4-methylenedioxyphenyl) or pharmaceutically permissible acid addition salt thereof, e.g. 1-[4-(3-cyclohexylamino-2- hydroxypropoxy)phenyl]-1-(4-hydroxyphenyl)-2-phenyl-1-butene. The compound can be produced from a compound expressed by formula II (R6 is H or OH) and a compound expressed by formula III through compounds expressed by formula IV and formula V. Oral dose of the objective compound is preferably about 1-500mg/adult and content of the compound per one unit of pharmaceutical preparation is preferably about 0.5-50mg.