An exemplary lens module (30) includes a lens barrel (31), a focusing mechanism (40), a resilient member (70), and a bottom seat (50). The lens barrel is mounted with at least one lens (36) therein and is fixed to one end of the focusing mechanism. One end of the resilient member resists the focusing mechanism and the other opposite end of the resilient member resists the bottom seat. The focusing mechanism is for controlling an amount of expansion permitted within the resilient member. The amount of expansion of the resilient member determines a degree of focus achieved by the lens module.