An upright vacuum cleaner (1) is provided, including a brushroll assembly (100), a motor assembly (200) and a body assembly (300). The brushroll assembly (200) includes a brushroll casing (12) and a brushroll (11). The motor assembly (200) includes a motor housing (21) and a motor (22), and the motor (22) drives the brushroll (11) to roll via a drive belt (13). The body assembly (300) includes a body (31) and a bridging member (32) mounted to the body (31), and the bridging member (32) is pivotably connected with the motor housing (21) to allow the body (31) to be rotatable between an upright position and an oblique position. When the body (31) is rotated from the upright position to the oblique position, the bridging member (32) pushes the brushroll casing (12) to move in a direction running away from the motor housing (21) so as to tension the drive belt (13).