A hinge assembly comprising: a housing having a chamber defined therein, an arm pivotably connected to the housing, a spring located in the chamber to provide a force to allow the pivotal movement between the housing and the arm; a damping device having a maintaining member secured in the chamber of the housing and the maintaining member having a path, a damper located in the path and located corresponding to the arm, the damper having a piston rod; an adjustment member movably connected to the maintaining member and having a protruded portion, characterized in that the protruded portion of the adjustment member is protruded into the maintaining member and located corresponding to the piston rod of the damper; when the adjustment member is moved to a first position relative to the maintaining member, the protruded portion of the adjustment member is located toward the piston rod of the damper, when the housing is closed relative to the arm, the damper is pushed by the arm, so that the piston rod of the damper contacts the protruded portion of the adjustment member and retracts to perform damping function, and when the adjustment member is moved to a second position relative to the maintaining member, the protruded portion of the adjustment member is moved away from the piston rod of the damper, when the housing is closed relative to the arm, the piston rod and the damper are integrally moved relative to the maintaining member towards the adjustment member and the piston rod of the damper cannot contact the protruded portion of the adjustment member, so that no damping function is available. a housing having a chamber defined therein, an arm pivotably connected to the housing, a spring located in the chamber to provide a force to allow the pivotal movement between the housing and the arm; a damping device having a maintaining member secured in the chamber of the housing and the maintaining member having a path, a damper located in the path and located corresponding to the arm, the damper having a piston rod; an adjustment member movably connected to the maintaining member and having a protruded portion, characterized in that the protruded portion of the adjustment member is protruded into the maintaining member and located corresponding to the piston rod of the damper; when the adjustment member is moved to a first position relative to the maintaining member, the protruded portion of the adjustment member is located toward the piston rod of the damper, when the housing is closed relative to the arm, the damper is pushed by the arm, so that the piston rod of the damper contacts the protruded portion of the adjustment member and retracts to perform damping function, and when the adjustment member is moved to a second position relative to the maintaining member, the protruded portion of the adjustment member is moved away from the piston rod of the damper, when the housing is closed relative to the arm, the piston rod and the damper are integrally moved relative to the maintaining member towards the adjustment member and the piston rod of the damper cannot contact the protruded portion of the adjustment member, so that no damping function is available.