A micro-speaker includes a frame, a yoke received in the frame, a connecting plate received in the yoke, a magnet received in the yoke, a pole plate attached onto the magnet, a diaphragm attached to the frame, a voice coil positioned on the connecting plate and surrounding the magnet, and a case covering the diaphragm. The diaphragm includes a central area in a center thereof, a joint area at an outer periphery thereof, and a connecting area between the central area and the joint area. The connecting plate includes a central portion formed in a central thereof for connecting with the central area of the diaphragm, and an oblique wall obliquely connecting to the central portion. The voice coil is wrapped on the oblique wall.