A package structure of MEMS microphone includes a carrier, a molding compound, a microphone chip and a lid. The carrier has an upper surface on which a chip region is defined, a lower surface and at least one guiding hole communicating with the upper surface and the lower surface. The molding compound has a ring wall portion surrounding the chip region and a filling portion filling the guiding hole. The microphone chip sited on the chip region of the carrier electrically connects the carrier. The lid is jointed to the ring wall portion of the molding compound. In this invention, the guiding hole is used to enable the ring wall portion and the filling portion of the molding compound to be formed integrally, so as to enhance the stability of the molding process and strengthen the structure of the carrier.