The utility model discloses a regulation structure that leans forward of manual regulation seat, including the locking piece, the locking pinion rack, the preceding pinion rack of violently managing, first connecting rod, the second connecting rod, violently manage, upper seat body and lower pedestal, upper seat body's rear end both sides are passed through the primary shaft and are in the same place with lower pedestal pin joint, the locking piece passes through the secondary shaft pin joint under on the pedestal, the pin joint of third axle is passed through on upper seat body in the upper end of locking pinion rack, preceding rear end of violently managing the pinion rack the and violently pipe is together fixed, the both ends of violently managing are together fixed with upper seat body, first spacing groove has been seted up to the preceding pinion rack of violently managing, the last spacing post of upper seat body is arranged in first spacing groove, the one end of second connecting rod is fixed and is violently managed, the other end of second connecting rod is articulated with first connecting rod, the other end of first connecting rod is with the pedestal is articulated down, the locking piece has the unblock handle, the unblock handle is arranged in the second spacing groove of pedestal down, the locking pinion rack is replaced to the locking piece, and pinion rack contact meshing is violently managed together with preceding to the locking pinion rack. The utility model discloses adjust convenient operation, the operating physical force is little, and the seat can not rock.