The present invention provides a comb-shaped epoxy resin represented by the following formula (1): ##STR00001## in the formula (1), X.sub.1 and X.sub.2 represent a divalent group having a residue selected from xanthene residue, biphenylene residue, hydrogenated bisphenol residue, alkylene residue and polyoxyalkylene residue, each may having a methyl group or a ethyl group as a substituent, and at least one of them is an aromatic residue, Y represents a polymer chain such as linear polymer chain, a number average polymerization degree being 5 to 2000, and n (number average polymerization degree) represents an integer within a range of 3 to 200, and to a method for preparing the comb-shaped epoxy resin.