Disclosed is a loudspeaker, comprising a casing (7) and a vibration system. The vibration system comprises a vibrating diaphragm (3) and a sound coil (4) fixed at a side of the vibrating diaphragm. A joint portion is arranged at an edge of the vibrating diaphragm (3). The joint portion is bonded and fixed to the casing (7). A recessed adhesive accommodating structure (71) is arranged at an end face connecting the casing (7) to the joint portion. The adhesive accommodating structure (71) is arranged corresponding to an adhesive surface between the vibrating diaphragm (3) and the casing (7), and is an annular structure. According to the present invention, the loudspeaker's acoustic performance is stabilized, while the vibrating diaphragm (3) and the casing (7) can be firmly connected to each other.