A suspension assembling structure comprising: a suspension link through which a road wheel and a vehicle body are pivotably connected to each other; a coil spring interleaved between the suspension link and the vehicle body in such a manner that a spring axis of the coil spring is arranged in a substantially vertical direction of the vehicle body; a spring seat interleaved between the suspension link and a lower end of the coil spring; the suspension link having an engagement hole formed in a mounting face for the spring seat; the spring seat comprising: (a) a seat body; (b) a protrusion formed on a lower face of the seat body and configured to be brought into engagement with the suspension link by insertion into the engagement hole; (c) a cylindrical portion located on an upper face of the seat body and configured to be fitted into the lower end of the coil spring; and (d) at least one flange formed on an outer peripheral surface of the cylindrical portion in a manner so as to radially protrude through a clearance space defined between adjacent wires of the coil spring, and configured to hold the wire of a first turn at the lower end of the coil spring, while being kept in abutted-engagement with an upper face of the first turn, wherein said at least one flange comprises two flanges (53, 53) formed on the outer peripheral surface of the cylindrical portion at respective circumferential positions (P3-P4), characterized in that at least one of the two flanges (53, 53) is laid out on a straight line passing through the coil axis and perpendicular to an axis of oscillation motion of the suspension link on a side of the vehicle body. a suspension link through which a road wheel and a vehicle body are pivotably connected to each other; a coil spring interleaved between the suspension link and the vehicle body in such a manner that a spring axis of the coil spring is arranged in a substantially vertical direction of the vehicle body; a spring seat interleaved between the suspension link and a lower end of the coil spring; the suspension link having an engagement hole formed in a mounting face for the spring seat; the spring seat comprising: (a) a seat body; (b) a protrusion formed on a lower face of the seat body and configured to be brought into engagement with the suspension link by insertion into the engagement hole; (c) a cylindrical portion located on an upper face of the seat body and configured to be fitted into the lower end of the coil spring; and (d) at least one flange formed on an outer peripheral surface of the cylindrical portion in a manner so as to radially protrude through a clearance space defined between adjacent wires of the coil spring, and configured to hold the wire of a first turn at the lower end of the coil spring, while being kept in abutted-engagement with an upper face of the first turn, wherein said at least one flange comprises two flanges (53, 53) formed on the outer peripheral surface of the cylindrical portion at respective circumferential positions (P3-P4), (a) a seat body; (b) a protrusion formed on a lower face of the seat body and configured to be brought into engagement with the suspension link by insertion into the engagement hole; (c) a cylindrical portion located on an upper face of the seat body and configured to be fitted into the lower end of the coil spring; and (d) at least one flange formed on an outer peripheral surface of the cylindrical portion in a manner so as to radially protrude through a clearance space defined between adjacent wires of the coil spring, and configured to hold the wire of a first turn at the lower end of the coil spring, while being kept in abutted-engagement with an upper face of the first turn, wherein said at least one flange comprises two flanges (53, 53) formed on the outer peripheral surface of the cylindrical portion at respective circumferential positions (P3-P4), characterized in that at least one of the two flanges (53, 53) is laid out on a straight line passing through the coil axis and perpendicular to an axis of oscillation motion of the suspension link on a side of the vehicle body.