A wind-turbine tower, comprising: a base structure; and a tower body to be erected on the base structure, wherein the base structure includes: a cylindrical member (10;12) having an inner diameter (D F) larger than an outer diameter (D T) of a root part of the tower body and being disposed along an upward and downward direction; and a stiffening plate mounted to an inner wall surface of the cylindrical member (10;12) so as to extend inward in a radial direction of the cylindrical member (10;12); characterized in that the tower body includes a tower-body side flange disposed along a circumferential direction of the tower body at a lower end of the root part of the tower body, and the base structure further includes a load transmitting part, disposed between the stiffening plate and the root part of the tower body, for transmitting a load of the root part of the tower body to the cylindrical member (10;12), wherein the load transmitting part includes: a pipe-shaped member disposed along the upward and downward direction, at a radially inner side of the cylindrical member (10;12) and between the tower body and the stiffening plate; and a base-structure side flange disposed on an upper end portion of the pipe-shaped member, the base-structure side flange extending along a circumferential direction of the pipe-shaped member and being engaged with the tower-body side flange. a base structure; and a tower body to be erected on the base structure, wherein the base structure includes: a cylindrical member (10;12) having an inner diameter (D F) larger than an outer diameter (D T) of a root part of the tower body and being disposed along an upward and downward direction; and a stiffening plate mounted to an inner wall surface of the cylindrical member (10;12) so as to extend inward in a radial direction of the cylindrical member (10;12); a cylindrical member (10;12) having an inner diameter (D F) larger than an outer diameter (D T) of a root part of the tower body and being disposed along an upward and downward direction; and a stiffening plate mounted to an inner wall surface of the cylindrical member (10;12) so as to extend inward in a radial direction of the cylindrical member (10;12); characterized in that the tower body includes a tower-body side flange disposed along a circumferential direction of the tower body at a lower end of the root part of the tower body, and the base structure further includes a load transmitting part, disposed between the stiffening plate and the root part of the tower body, for transmitting a load of the root part of the tower body to the cylindrical member (10;12), wherein the load transmitting part includes: a pipe-shaped member disposed along the upward and downward direction, at a radially inner side of the cylindrical member (10;12) and between the tower body and the stiffening plate; and a base-structure side flange disposed on an upper end portion of the pipe-shaped member, the base-structure side flange extending along a circumferential direction of the pipe-shaped member and being engaged with the tower-body side flange. a pipe-shaped member disposed along the upward and downward direction, at a radially inner side of the cylindrical member (10;12) and between the tower body and the stiffening plate; and a base-structure side flange disposed on an upper end portion of the pipe-shaped member, the base-structure side flange extending along a circumferential direction of the pipe-shaped member and being engaged with the tower-body side flange.