Controlling the volume velocity of vibration plate has previously been shown to be a good strategy to reduce its overall sound radiation and vibration energy. The shape of the first radiation mode corresponds to the volume velocity of the plate at the low frequency. By measuring the vibrating velocity distributions at few points of a plate and solving the underdetermined equations of the acoustic radiation mode expansion, the desired adjoin coefficients of radiation modes as well as the volume velocity and energy of vibration structure can be obtained. Numerical analysis indicates that the volume velocity and the vibration energy are consistent with the theoretical values. In addition, the above theory can be used to design the simple and highly operable active controlling system.