A variable compression ratio engine, comprising: means for setting a compression ratio corresponding to a state of the engine comprising: a piston disposed in a cylinder bore and defining, at least in part, a combustion chamber; and a variable compression ratio mechanism connected to the piston for causing a top dead center position of the piston to vary, wherein the variable compression ratio mechanism comprises: a first link pivotably coupled to the piston; a second link pivotably coupled to the first link and pivotably fitted to a crankshaft; a control shaft rotatably supported by a cylinder block and parallel to the crankshaft, that includes an eccentric axis portion eccentric relative to a rotational axial center of the control shaft; and a third link rotatably coupled to the second link by a coupling pin and that is pivotable about a pivotal axis center coincident with the eccentric axis portion of the control shaft; means for actuating an actuator so that the compression ratio is set; means for determining whether a state of the engine is either a state in which the load on the actuator is not limited, or a state in which the load on the actuator is limited; and means for limiting the load on the actuator during the actuation in the engine state in which the load on the actuator is limited, the engine being characterized in that the engine state in which the load on the actuator is limited is a combustion state of the engine under a condition where an action line of a load acting between the third link and the eccentric axis portion is spaced apart from a rotation center of the control shaft at a predetermined distance or larger. means for setting a compression ratio corresponding to a state of the engine comprising: a piston disposed in a cylinder bore and defining, at least in part, a combustion chamber; and a variable compression ratio mechanism connected to the piston for causing a top dead center position of the piston to vary, wherein the variable compression ratio mechanism comprises: a first link pivotably coupled to the piston; a second link pivotably coupled to the first link and pivotably fitted to a crankshaft; a control shaft rotatably supported by a cylinder block and parallel to the crankshaft, that includes an eccentric axis portion eccentric relative to a rotational axial center of the control shaft; and a third link rotatably coupled to the second link by a coupling pin and that is pivotable about a pivotal axis center coincident with the eccentric axis portion of the control shaft; a piston disposed in a cylinder bore and defining, at least in part, a combustion chamber; and a variable compression ratio mechanism connected to the piston for causing a top dead center position of the piston to vary, wherein the variable compression ratio mechanism comprises: a first link pivotably coupled to the piston; a second link pivotably coupled to the first link and pivotably fitted to a crankshaft; a control shaft rotatably supported by a cylinder block and parallel to the crankshaft, that includes an eccentric axis portion eccentric relative to a rotational axial center of the control shaft; and a third link rotatably coupled to the second link by a coupling pin and that is pivotable about a pivotal axis center coincident with the eccentric axis portion of the control shaft; a first link pivotably coupled to the piston; a second link pivotably coupled to the first link and pivotably fitted to a crankshaft; a control shaft rotatably supported by a cylinder block and parallel to the crankshaft, that includes an eccentric axis portion eccentric relative to a rotational axial center of the control shaft; and a third link rotatably coupled to the second link by a coupling pin and that is pivotable about a pivotal axis center coincident with the eccentric axis portion of the control shaft; means for actuating an actuator so that the compression ratio is set; means for determining whether a state of the engine is either a state in which the load on the actuator is not limited, or a state in which the load on the actuator is limited; and means for limiting the load on the actuator during the actuation in the engine state in which the load on the actuator is limited, the engine being characterized in that the engine state in which the load on the actuator is limited is a combustion state of the engine under a condition where an action line of a load acting between the third link and the eccentric axis portion is spaced apart from a rotation center of the control shaft at a predetermined distance or larger.