A housing (10) of a portable electronic device includes an upper housing (11), a lower housing (12) and a protecting component (13). The upper housing defines a first latching member (1112) therein. The lower housing defines a second latching member (121) therein. The protecting component is assembled between the upper housing and the lower housing for preventing dust and vapor from entering the electronic device and defines a first latching portion (1313) corresponding to the first latching member and a second latching portion (1314) corresponding to the second latching member. The first latching portion and the second latching member respectively cooperate with the first latching member and the second latching member to assemble the upper housing, the lower housing and the protecting component together.