Heat-sensitive recording material

A heat-sensitive recording material comprising a base sheet and a heat-sensitive record layer formed over the base sheet and comprising a colorless or pale-colored basic dye and a color developing material capable of forming a color when contacted with the dye, the heat-sensitive recording material being characterized in that the heat-sensitive record layer contains as the color developing material at least one multi-valent metal salt of an indole-2-carboxylic acid derivative represented by the formula ##STR5## wherein

• R.sub.1 is hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted alkynyl group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted alkylcarbonyl group or substituted or unsubstituted arylcarbonyl group;
• and
• R.sub.2 through R.sub.6 each represent hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted alkynyl group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted cycloalkyloxy group, substituted or unsubstituted alkenyloxy group, substituted or unsubstituted alkynyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted aralkyloxy group, substituted or unsubstituted alkylcarbonyloxy group, substituted or unsubstituted arylcarbonyloxy group, substituted or unsubstituted alkylcarbonyl group, substituted or unsubstituted arylcarbonyl group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted amino group, halogen atom, nitro group, cyano group or hydroxyl group.