A method of manufacturing a semiconductor package structure is provided. A heat-conductive block is adhered to a portion of a second surface of a conductive substrate via a first adhesive layer. An opening is formed by performing a half-etching process on a first surface of the conductive substrate. The remaining conductive substrate is patterned to form leads and expose a portion of the heat-conductive block. Each lead has a first portion and a second portion. A thickness of the first portion is greater than a thickness of the second portion. A first lower surface of the first portion and a second lower surface of the second portion are coplanar. A chip is disposed on the exposed portion of the heat-conductive block and electrically connected to the second portions of the leads. A first bottom surface of the heat-conductive block and a second bottom surface of a molding compound are coplanar.