A silver halide photographic light-sensitive material contains a methine compound represented by the following formula: ##STR1## wherein Y.sup.1 is a group which is clearable by a nucleophile; Z.sup.1 is --O--, --S-- or other; Z.sup.2 is --S--; A and B are each independently hydrogen, halogen, alkyl, aryl or a heterocyclic group; A and B may be linked to each other to form an unsaturated aliphatic ring or an aromatic ring; and Q.sup.1 is a methine or polymethine group which may have a heterocyclic group. A novel methine compound is also disclosed.