Abstract: A device for preventing reverse rotation of a rotor in spinning reels is disclosed. In the device, an operational control shaft is fitted over a connection shaft and biased by a plate spring generating an elastic force. The operational control shaft has two connecting arms extending in different directions. The connecting arms are movably coupled to longitudinal holes of a reverse rotation prevention claw pivoted to a reel body, thereby coupling the operational control shaft to the claw at two coupling points. The turning force of the operational control shaft is thus precisely transmitted to the claw, thereby precisely performing the reverse rotation prevention operation. In this device both the connection shaft and the operational control shaft can smoothly rotate as they are supported by the plate spring.