The present invention provides a window covering with a safety cord releaser. The cord releaser includes a hanging member connected to an end of a cord of the window covering and a blocking member connected to a valance of the window covering. The hanging member has an engaging portion, which has an engaging space, a gateway to be an entrance of the engaging space, and two edges at opposite sides of the gateway. The blocking member has a blocking portion to be detachably engaged with the engaging space of the hanging portion. The block portion has an oval cross section and the engaging space of the hanging member is complementary to it that only at a specific angle the blocking member is able to be engaged and disengaged with the hanging member.