A mounting apparatus includes a bottom plate, a bracket fixed to the bottom plate, and a clamp rotatably mounted to the bottom plate. The bracket includes a first and a second mounting piece. The second mounting piece defines a mounting groove for receiving an edge of a circuit board. The first mounting piece includes a mounting portion, and a fixing piece extending from the mounting portion. The mounting portion includes a post for engaging in a hole of the circuit board. The fixing piece defines a clamping hole. The clamp includes an elastic piece, and a plurality of clips. The elastic piece is configured to move with the clamp to insert through the clamping hole and catch the first mounting piece. The clips are configured to move with the clamp to clip the circuit board to the fixing piece.