A wind turbine rotor supported on a nacelle of a wind turbine to be freely rotatable, the wind turbine rotor comprising: at least two blades; a hub to which the at least two blades are attached; a spinner disposed so as to cover the hub, the spinner including an insulating material; a blade lightning-protection system provided for each of the at least two blades; and the wind turbine rotor being characterized in that it further comprises: a spinner lightning-protection system provided for the spinner, the spinner lightning-protection system including at least one receptor (21,22), wherein the at least one receptor (21,22) is disposed so that, when being projected on a rotational plane of the wind turbine rotor, at least a part of the at least one receptor (21,22) being projected is positioned within an angular range (α) corresponding to a circular-arc region between blade root portions of adjacent two of the at least two blades, the circular-arc region being a portion of a virtual circle, on the rotational plane, passing through the blade root portions of the at least two blades, and wherein the at least one receptor (21,22) is disposed so that, when being projected on a plane including a rotation axis of the wind turbine rotor, at least a part of the at least one receptor (21,22) being projected is positioned at a front side with respect of the blade root portions of the at least two blades, the front side being a hub side and a rear side being a nacelle side in an axial direction of the rotation axis, wherein the at least one receptor (21, 22) is disposed on an outer circumferential surface of the spinner. at least two blades; a hub to which the at least two blades are attached; a spinner disposed so as to cover the hub, the spinner including an insulating material; a blade lightning-protection system provided for each of the at least two blades; and the wind turbine rotor being characterized in that it further comprises: a spinner lightning-protection system provided for the spinner, the spinner lightning-protection system including at least one receptor (21,22), wherein the at least one receptor (21,22) is disposed so that, when being projected on a rotational plane of the wind turbine rotor, at least a part of the at least one receptor (21,22) being projected is positioned within an angular range (α) corresponding to a circular-arc region between blade root portions of adjacent two of the at least two blades, the circular-arc region being a portion of a virtual circle, on the rotational plane, passing through the blade root portions of the at least two blades, and wherein the at least one receptor (21,22) is disposed so that, when being projected on a plane including a rotation axis of the wind turbine rotor, at least a part of the at least one receptor (21,22) being projected is positioned at a front side with respect of the blade root portions of the at least two blades, the front side being a hub side and a rear side being a nacelle side in an axial direction of the rotation axis, a spinner lightning-protection system provided for the spinner, the spinner lightning-protection system including at least one receptor (21,22), wherein the at least one receptor (21,22) is disposed so that, when being projected on a rotational plane of the wind turbine rotor, at least a part of the at least one receptor (21,22) being projected is positioned within an angular range (α) corresponding to a circular-arc region between blade root portions of adjacent two of the at least two blades, the circular-arc region being a portion of a virtual circle, on the rotational plane, passing through the blade root portions of the at least two blades, and wherein the at least one receptor (21,22) is disposed so that, when being projected on a plane including a rotation axis of the wind turbine rotor, at least a part of the at least one receptor (21,22) being projected is positioned at a front side with respect of the blade root portions of the at least two blades, the front side being a hub side and a rear side being a nacelle side in an axial direction of the rotation axis, wherein the at least one receptor (21, 22) is disposed on an outer circumferential surface of the spinner.