A child's sleeping garment including an envelope, a pillow detachably associated with upper edges of the envelope, an elongating bag detachably associated with lower edges of the envelope for elongating the length thereof, and two sleeves detachably secured to the envelope, wherein the envelope has a front wall, a rear wall, a neck opening formed at upper edge of the envelope and two arm openings respectively formed on two side edges thereof, the front wall of the envelope being divided into two flaps which are detachably connected by a zipper whereby a child or an infant in the envelope can be kept warm and comfortable without any possibility of strangling himself through his turning movements in sleep, the sleeping garment permitting the child to do free movement of the legs and arms without being entangled and exposed to cold.