IN THIS ARTICLE, WE PROPOSE A MATHEMATICAL MODEL FOR ONE-DIMENSIONAL HEAT CONDUCTION IN A THREE-LAYERED SOLID CONSIDERING THAT AN INTERFACIAL CONDITION IS PRESENT FOR THE TEMPERATURE AND HEAT FLUX CONDITIONS BETWEEN THE LAYERS. THE NUMERICAL APPROACH IS DEVELOPED BY CONSTRUCTING A FINITE DIFFERENCE SCHEME TO SOLVE THE INITIAL BOUNDARY?INTERFACE PROBLEM. THE NUMERICAL SCHEME IS DESIGNED BY CONSIDERING THE ACCURACY OF THE MODEL ON THE INNER PART OF EACH LAYER, THEN EXTENDING TO THE INTERFACES AND BOUNDARIES BY INCORPORATING THE CONTINUOUS INTERFACIAL CONDITIONS. THE FINITE DIFFERENCE SCHEME IS UNCONDITIONALLY STABLE, CONVERGENT, AND EASY TO IMPLEMENT SINCE IT CONSISTS OF THE SOLUTION OF TWO ALGEBRAIC SYSTEMS. WE PROVIDE THREE NUMERICAL EXAMPLES TO CONFIRM THAT OUR NUMERICAL APPROXIMATION IS CONSISTENT WITH THE ANALYTICAL SOLUTION AND THE PHYSICAL PHENOMENON.