Disclosed is a fishing line spool assembly including an open body frame, wherein a fishing line spool is mounted between two side plates of the body frame at an open end, has a central bore, and is rotatably sandwiched between the two side plates by a clamping adjustable device inserted through the central bore of the fishing line spool and bores of the two side plates. The body frame is provided with a connection device for connecting to a fishing rod. With the present invention, the clamping force applied on the fishing line spool by the two side plates can by adjusted by the clamping adjustable device. When the fishing line in the fishing line spool is drawn by a fishing reel, the clamping force on the fishing line spool by the body frame will function as a brake against the rotation of the fishing line spool.
