A battery cover latch mechanism includes a housing, a battery cover, and a latching part. The housing includes a clasp positioned thereon. The battery cover includes a guiding portion and a resisting block facing the guiding portion. The latching part includes a button and a resilient bar assembled on the battery cover. The button includes a hook resisting the resisting block. The button slidably and releasably latches to the clasp to lock the battery cover to the housing or release the battery cover from the housing. The invention also discloses a portable electronic device using the battery cover latch mechanism.