According to the fact that both wear and vibration of gears consume the ir system energy, a method of modeling and calculation of the correlation betwee n the wear and vibration is proposed based on their energy consumption. In this work, the wear energy consumption of the gears is expressed by their debris elem ent mass fraction obtained from spectral anａlysis; the vibration energy consump ti on expressed by the root mean square value of vibration velocity in the time dom ain, and the correlation between wear and vibration is defined by their relative deviation in the decibel scale. Experimental results show that the wear and vi b ration of gears are highly correlated, which provides a new method for fault dia gnosis of a gearbox.