An electric power distribution panel is provided. The electric power distribution panel includes a first input bus, a second input bus, a plurality of brackets and a plurality of circuit breaker modules. The first and second input buses are coupled to a first power source and a second power source respectively. The plurality of brackets is electrically connected to the first and second input buses. The plurality of circuit breaker modules are assembled to the plurality of brackets respectively. Each of the plurality of circuit breaker modules includes a circuit breaker and an adapter detachably assembled to the circuit breaker. In each of the plurality of circuit breaker modules, the circuit breaker is electrically connected to the first input bus when the adapter is removed from the circuit breaker, and the circuit breaker is electrically connected to the second input bus when the adapter is assembled to the circuit breaker.