Abstract: A protective circuit for bipolar integrated circuits to prevent inadvertent damage caused by electrostatic discharge includes a plurality of clamping networks (12a-12n). Each of the plurality of clamping networks (12a-12n). is connected between a corresponding one of a number of external input/output pins (P1-Pn) of the integrated circuit and a common bus line (14) which is connected to an external substrate pin (PS). Each of the plurality of clamping networks (12a-12n) includes a silicon-controlled rectifier (T1), a diode (D1), a first resistor (R1) and a second resistor (R2). When any one of the number of external input/output pins (P1-Pn) receives a voltage higher than a predeter-mined value and any remaining one of the external input/output pins (P1-Pn) contacts a ground potential, a discharge path is formed by a single silicon-controlled rectifier and a single diode so as to protect an internal circuit portion.