An alkali-soluble resin having a polyaromatic group and a photosensitive composition comprising the alkali-soluble resin. The alkali-soluble resin comprises the following recurring units: wherein each of R.sub.1, R.sub.2, and R.sub.3, independently, is H or CH.sub.3; R.sub.4 is a substituted or unsubstituted polyaromatic derivative containing carbon and optionally containing one or more heteroatoms of oxygen, nitrogen and sulfur; X is alkyl, benzyl, or hydroxyl; each of n.sub.1 and n.sub.2, independently, is an integer of 0-8; and a, b, and c are integers when a and c respectively are not zero.