A dynamic pressure sensing structure used in a condenser microphone includes an upper electrode plate, a lower electrode plate, a spacer and a substrate, wherein the upper and lower electrode plates are separated by the spacer and form a resonance cavity with the substrate. The upper electrode plate comprises a flat vibration area and a surrounding flexible area connected thereto. The lower electrode plate comprises a sensible electrode and an actuation electrode surrounding the sensible electrode. The plate is in connection with the flexible area so that a capacitor is formed between the sense area and the flat vibration area. The actuation electrode provides a polarization voltage to generate an electrostatic force, thereby attract the flexible vibration area to curve downwards so that the flat vibration area moves in a flat state and a distance between the flat vibration area and the sensible electrode is varied correspondingly.