A C-clip tool includes a first part and a second part. A first arm and a second arm are connected between the first and second parts. The second part has a reception hole and a rod is located at the mediate portion of the reception hole. Two enlarged holes are located on two ends of the reception hole and communicate with the reception hole. A resilient plate is located in the reception hole and two pillars are connected to the resilient plate. A push member has a block which optionally contacts one of the two pillars. Two operation members are respectively connected to the first and second arms. The operation members are replaceable to operate on different sizes of C-clips.