A hinge assembly includes a pivot shaft, a first leaf, a fixing leaf, a restricting member, a deformable member, two limiting blocks, and a fastening member. The rotatable leaf is non-rotatably connected to the pivot shaft and the fixing leaf is rotatably connected to the pivot shaft. The restricting member and the deformable member are rotatably sleeved on the pivot shaft. The restricting member defines two positioning grooves. The deformable member includes a base plate and two protrusions extending substantially perpendicularly from the base plate. The limiting blocks are partially received in the positioning grooves and connected to the deformable member. When the rotatable leaf is rotated, the limiting blocks slide out of the positioning grooves to press the base plate of the deformable member such that the deformable member becomes elastically deformed. The fastening member is fixed on an end of the pivot shaft.