A housing of portable electronic device includes a glass member and a plastic member formed in the glass member. The glass member includes a base plate, a plurality of sidewalls substantially vertically extending from the base plate. Each two neighboring sidewalls form a gap portion. The base plate includes a first inner surface, and each sidewall includes a second inner surface and an outer surface opposite the second inner surface. The plastic member fit closely against the first inner surface and the second inner surface. The plastic member further includes at least one protrusion portion positioned at the outer surface of the sidewalls and covered above at least one of the gap portions. A method of manufacturing the housing is also provided.