To provide a novel resin (composition) prepared without using any formaldehyde in the synthesis process and having a viscosity high to such an extent that it is desirable as a resin used in the preparation of widely applicable inks or having a high molecular weight.

This resin (composition) is obtained by reacting under heating a rosin, an α,β-unsaturated carboxylic acid or an anhydride thereof, an aliphatic polybasic acid, an organopolysiloxane such as a hydroxyl-terminated linear polydimethylsiloxane, and a polyhydric alcohol. More particularly, a resin or a resin composition obtained by performing the above reaction by using 1-15 pts.wt., per 100 pts.wt. rosin, α,β-unsaturated carboxylic acid or anbydride thereof.