The present invention relates to an assembly structure of a diaphragm for a microspeaker. The present invention discloses a bonding structure of a diaphragm for a microspeaker, the boding structure comprising: a suspension including a central portion, an outer peripheral portion, and a connecting portion connecting the central portion and the outer peripheral portion; and a side diaphragm including an inner peripheral portion and an outer peripheral portion, which are attached to the central portion and outer peripheral portion of the suspension, respectively, and a dome portion, which projects between the inner peripheral portion and the outer peripheral portion, wherein the suspension and the side diaphragm are attached by thermal compression.