A hinge assembly includes a first bracket, a second bracket, a damping member, and a torsion resilient member. The first bracket defines a damping protrusion. The second bracket is rotatable relative to the first bracket. The damping member defines a depression. The damping protrusion is configured to engage with the depression. The torsion resilient member urges the first bracket to rotate relative to the second bracket and the damping member. The engagement of damping protrusion and the depression prevents the first bracket from rotating when the first bracket rotates through a predetermined angle. When the first bracket rotates through the predetermined angle relative to the second bracket and the damping member, the first bracket together with the damping member are rotatable relative to the second bracket to any desired angle.