A diaphragm for a speaker, the diaphragm comprising a suspension edge and a vibration unit, and a supporting frame, wherein the suspension edge comprises: an inner suspension edge portion for connecting with the vibration unit, wherein said inner suspension edge portion comprises an inner suspension edge body and at least two inner side elastic ribs radially protruded from said inner suspension edge body, wherein each of said inner side elastic ribs forms a bulge on a first side of said inner suspension edge portion and a flute on an opposite second side thereof; and an outer suspension edge portion for connecting with the supporting frame, wherein said outer suspension edge portion comprises an outer suspension edge body and at least two outer side elastic ribs radially protruded from said outer suspension edge body, wherein each of said outer side elastic ribs forms a protrusion on a first side of said outer suspension edge portion and a groove on an opposite second side thereof, characterized in that said supporting frame comprises a first support frame and a second support frame connected with said first support frame, wherein said suspension edge is connected to said first support frame and said second support frame is adapted to support a magnetic coil unit of the speaker; wherei said first support frame comprises a plurality of wave-shaped protruding teeth annularly arranged inside and an indented groove formed between two adjacent protruding teeth, wherein each outer side elastic ribs are outwardly extended from an external edge of two adjacent protruding teeth which form said indented groove; and wherein said vibration unit comprises a plurality of wave-shaped convex teeth arranged on an outer side and a notch formed between two adjacent convex teeth, wherein each inner side elastic ribs are outwardly extended from an outer edge of two adjacent convex teeth. an inner suspension edge portion for connecting with the vibration unit, wherein said inner suspension edge portion comprises an inner suspension edge body and at least two inner side elastic ribs radially protruded from said inner suspension edge body, wherein each of said inner side elastic ribs forms a bulge on a first side of said inner suspension edge portion and a flute on an opposite second side thereof; and an outer suspension edge portion for connecting with the supporting frame, wherein said outer suspension edge portion comprises an outer suspension edge body and at least two outer side elastic ribs radially protruded from said outer suspension edge body, wherein each of said outer side elastic ribs forms a protrusion on a first side of said outer suspension edge portion and a groove on an opposite second side thereof, characterized in that said supporting frame comprises a first support frame and a second support frame connected with said first support frame, wherein said suspension edge is connected to said first support frame and said second support frame is adapted to support a magnetic coil unit of the speaker; wherei said first support frame comprises a plurality of wave-shaped protruding teeth annularly arranged inside and an indented groove formed between two adjacent protruding teeth, wherein each outer side elastic ribs are outwardly extended from an external edge of two adjacent protruding teeth which form said indented groove; and wherein said vibration unit comprises a plurality of wave-shaped convex teeth arranged on an outer side and a notch formed between two adjacent convex teeth, wherein each inner side elastic ribs are outwardly extended from an outer edge of two adjacent convex teeth.