Abstract: A spinning reel includes a body, which has two sliding plates coupled to two opposite lateral sides of the base thereof, a spool holder, which has a U-shaped frame pivotally mounted in the base of the body and a spool pivotally coupled to the U-shaped frame, a spool rotating mechanism, which has two pins axially movable to engage the spool and a gear set mounted on one pin for rotating the spool to take up a fishing line, and a spool biasing mechanism, which has a drive gear set, a operating bar for operation by a person to rotate the drive gear set, a driven gear set coupled to the drive gear set and rotatable to move the sliding plates in moving the pins of the spool rotating mechanism into engagement with spool or away from the spool, and a transmission device coupled between the driven gear set and the spool holder for causing the spool holder to be biased between a horizontal position and a vertical position upon rotation of the drive gear set by the operating bar.