A gear-shifting device for a vehicle is provided and includes a guide body that has a first end portion connected to a control shaft, installed so that a second end portion is rotated at the first end portion as an axis in a rotational displacement that corresponds to a selecting path to perform a selecting operation, and installed to be moved in a substantially straight displacement that corresponds to a shifting path along an axis direction of the first end portion to perform a shifting operation. A guide unit is disposed to distinguish each shifting path on the selecting path in which the second end portion of the guide body is rotated and is configured to guide the second end portion of the guide body to be movable along the shifting path.