Diagnosis system for fuel cell stack

The present invention relates to a fuel cell stack diagnosis system for diagnosing malfunction and state of a fuel cell stack. According to an embodiment of the present invention, a fuel cell stack diagnosis system includes a diagnosis control analyzer for analyzing a state of a fuel cell stack by measuring a voltage and current of the fuel cell stack; an AC signal generator for generating an AC signal for diagnosis according to a control of the diagnosis control analyzer; and an AC component driving device driven according to an AC signal outputted from the AC signal generator to include an AC component for diagnosing a current of the fuel cell stack. The diagnosis control analyzer diagnoses the fuel cell stack on the basis of the current and voltage of the fuel cell stack including the AC component passing a load.