A marine propulsion system for a marine vessel with a hull having a centerline (α) that extends in a forward-rearward direction of the hull, the marine propulsion system comprising: a main propulsion device configured to be attached to a stern of the hull on the centerline (α) with regard to a right-left direction of the marine vessel and including a main thruster configured to generate a thrust; an auxiliary propulsion device configured to be attached to the stern on one side of the centerline (α) of the hull with regard to the right-left direction, including an auxiliary thruster configured to generate a thrust, and having a maximum output smaller than a maximum output of the main propulsion device; and the auxiliary propulsion device further includes a tilt device configured to tilt up and tilt down an auxiliary propulsion device body of the auxiliary propulsion device with regard to an up-down direction of the hull, and is configured to tilt up the auxiliary propulsion device body with the tilt device, characterized by a remote control lever configured to switch between a neutral state in which the main thruster is stopped, a forward movement state in which the main thruster generates a forward thrust with regard to the forward-rearward direction of the hull, and a reverse movement state in which the main thruster generates a reverse thrust with regard to the forward-rearward direction of the hull; wherein the auxiliary propulsion device is configured to tilt up the auxiliary propulsion device body with the tilt device when the main propulsion device is switched from the neutral state to the forward movement state by the remote control lever while the auxiliary propulsion device body is tilted down. a main propulsion device configured to be attached to a stern of the hull on the centerline (α) with regard to a right-left direction of the marine vessel and including a main thruster configured to generate a thrust; an auxiliary propulsion device configured to be attached to the stern on one side of the centerline (α) of the hull with regard to the right-left direction, including an auxiliary thruster configured to generate a thrust, and having a maximum output smaller than a maximum output of the main propulsion device; and the auxiliary propulsion device further includes a tilt device configured to tilt up and tilt down an auxiliary propulsion device body of the auxiliary propulsion device with regard to an up-down direction of the hull, and is configured to tilt up the auxiliary propulsion device body with the tilt device, characterized by a remote control lever configured to switch between a neutral state in which the main thruster is stopped, a forward movement state in which the main thruster generates a forward thrust with regard to the forward-rearward direction of the hull, and a reverse movement state in which the main thruster generates a reverse thrust with regard to the forward-rearward direction of the hull; wherein the auxiliary propulsion device is configured to tilt up the auxiliary propulsion device body with the tilt device when the main propulsion device is switched from the neutral state to the forward movement state by the remote control lever while the auxiliary propulsion device body is tilted down.