A clutch system comprising: a clutch assembly connected or disconnected to an engine (Eg) of a vehicle, wherein a state of the clutch assembly is changed by pressing or releasing of an accelerator pedal or a brake pedal, and a rotary shaft assembly including: a power transmission device configured to transmit a motion of pressing or releasing of the accelerator pedal and the brake pedal into the clutch assembly, and a driving shaft connected to the power transmission device, and characterized in that the clutch system does not include a clutch pedal, and wherein the clutch assembly is in any one of states including: a first state configured to transmit a rotational force of the engine (Eg) to a transmission (Tr) by pressing the accelerator pedal; a second state in which the clutch assembly keeps transmitting the rotational force of the engine (Eg) to the transmission (Tr) through the input shaft, after releasing the accelerator pedal, a third state configured to cut off a connection between the engine (Eg) and the driving shaft by pressing the brake pedal, and a fourth state that is an initial transition state or intermediate state configured to transmit a rotational force of the engine (Eg) to the transmission by releasing the brake pedal, and wherein the driving shaft of the rotational body assembly connected to the power transmission device linearly is configured to move to a first direction by pressing the accelerator pedal, and the clutch assembly is positioned in the first state. a clutch assembly connected or disconnected to an engine (Eg) of a vehicle, wherein a state of the clutch assembly is changed by pressing or releasing of an accelerator pedal or a brake pedal, and a rotary shaft assembly including: a power transmission device configured to transmit a motion of pressing or releasing of the accelerator pedal and the brake pedal into the clutch assembly, and a driving shaft connected to the power transmission device, and characterized in that the clutch system does not include a clutch pedal, and wherein the clutch assembly is in any one of states including: a first state configured to transmit a rotational force of the engine (Eg) to a transmission (Tr) by pressing the accelerator pedal; a second state in which the clutch assembly keeps transmitting the rotational force of the engine (Eg) to the transmission (Tr) through the input shaft, after releasing the accelerator pedal, a third state configured to cut off a connection between the engine (Eg) and the driving shaft by pressing the brake pedal, and a fourth state that is an initial transition state or intermediate state configured to transmit a rotational force of the engine (Eg) to the transmission by releasing the brake pedal, and wherein the driving shaft of the rotational body assembly connected to the power transmission device linearly is configured to move to a first direction by pressing the accelerator pedal, and the clutch assembly is positioned in the first state. a power transmission device configured to transmit a motion of pressing or releasing of the accelerator pedal and the brake pedal into the clutch assembly, and a driving shaft connected to the power transmission device, and characterized in that the clutch system does not include a clutch pedal, and wherein the clutch assembly is in any one of states including: a first state configured to transmit a rotational force of the engine (Eg) to a transmission (Tr) by pressing the accelerator pedal; a second state in which the clutch assembly keeps transmitting the rotational force of the engine (Eg) to the transmission (Tr) through the input shaft, after releasing the accelerator pedal, a third state configured to cut off a connection between the engine (Eg) and the driving shaft by pressing the brake pedal, and a fourth state that is an initial transition state or intermediate state configured to transmit a rotational force of the engine (Eg) to the transmission by releasing the brake pedal, and wherein the driving shaft of the rotational body assembly connected to the power transmission device linearly is configured to move to a first direction by pressing the accelerator pedal, and the clutch assembly is positioned in the first state. a first state configured to transmit a rotational force of the engine (Eg) to a transmission (Tr) by pressing the accelerator pedal; a second state in which the clutch assembly keeps transmitting the rotational force of the engine (Eg) to the transmission (Tr) through the input shaft, after releasing the accelerator pedal, a third state configured to cut off a connection between the engine (Eg) and the driving shaft by pressing the brake pedal, and a fourth state that is an initial transition state or intermediate state configured to transmit a rotational force of the engine (Eg) to the transmission by releasing the brake pedal, and wherein the driving shaft of the rotational body assembly connected to the power transmission device linearly is configured to move to a first direction by pressing the accelerator pedal, and the clutch assembly is positioned in the first state.