NEW MATERIAL: A di(hydroxyphenyl)-containing compd. composed of ring- arylcyclobutene alkylated di(hydroxyphenyl)-containing compd. consisting of up to two aromatic rings at least one of which has an arylcyclobutene-containing substituent and having a phenyl group of a di(hydroxyphenyl)compd. bonded to a carbon atom of an aromatic 6membered ring in an arylcyclobutene portion through an alkylene linking group.

EXAMPLE: A compound represented by formula I (Alk is methylene, z is 0 and S is 0 or 1).

USE: A thermosetting monomer.

PREPARATION: In the presence of a Friedel-Crafts-alkylation catalyst, a compd. represented by formula II (X is aromatic) is reacted with an arylcyclobutenealkyl compd. represented by formula III (Ar is arylcyclobutene, R is alkylene and W is an electron withdrawing group) to obtain the di(hydroxyphenyl)-containing compd.