A short-circuit detecting apparatus and method of a heating system for a high voltage battery that includes a plurality of heaters, a short-circuited detection resistor, an A/D converter, and a Battery Management System (BMS). The plurality of heaters are connected to a high voltage battery to heat the high voltage battery. The short-circuit detection resistor is connected between the heaters to detect whether the heaters are short-circuited. The A/D converter is configured to sense a voltage applied across the short-circuit detection resistor. The BMS is configured to calculate a final operation value using the voltage applied across the short-circuit detection resistor and compare the final operation value with the value of battery pack voltage to detect whether the heaters are short-circuited.