A reinforcing apparatus for a lever handle of a door lock includes a housing fixed to a door and provided around a driving shaft of the door lock. The housing has a wall transverse to the driving shaft. The wall has a hole formed therethrough for passage of the driving shaft. A rotary member is mounted in the housing for rotating simultaneously with the driving shaft. The rotary member is sleeved on the driving shaft and has an engaging plate which projects axially from an outer peripheral edge thereof. A coiled spring is provided around the rotary member for biasing the rotary member to return and maintain the lever handle at its original unoperated position after the rotary member is rotated by the lever handle. The coiled spring has two legs extending radially outwardly to abut against the engaging plate. One of the legs is displaceable by the engaging plate. The housing further includes a stopping unit provided on the wall thereof. The stopping unit is aligned radially with and is located outwardly of the engaging pate when the lever handle is in the unoperated position. The other one of the legs is kept immobilized by the stopping unit when the rotary member rotates.