A heat developable light-sensitive material containing a compound represented by the general formula (I):[Ar.sub.n (R).sub.3-n CCO.sub.2 H].sub.l .multidot.B.sub.m (I)wherein ar represents an aryl group or a heterocyclic group; R represents a substituent other than an aryl group and a heterocyclic group; Ar and R may be bonded in a part thereof to form a ring; B represents a mono- or diacidic base which has a pKa of 7 or more and contains 12 or less carbon atoms; n represents an integer from 1 to 3; l and m each represents an integer of 1 or 2 and maintain a relationship in that a number of positive charge and a number of negative charge are equal; when n represents 1 or 2, two R's or Ar's may be the same or different, when n represents 3, three Ar's may be the same or different; and the substituent represented by Ar or R may be further substituted with a substituent. The compound represented by the general formula (I) is a base precursor which is stable at normal temperature but rapidly decomposes to release a base by heating and therefore the heat developable light-sensitive material containing the base precursor has excellent preservability and provides images having good image quality, i.e., low fog density and high image density upon a short period of developing time.