An E2O Q-switched Nd∶GdVO4 laser side - pumped by a diode-laser-array has been demonstrated. The characteristic difference between E2O Q-switched Nd∶GdVO4 and Nd∶YAG laser is analyzed in pump efficiency, Q-switched performance and temperature characteristics. An output energy of 27. 5mJ and a pulse width of 6. 4ns are obtained. The pump efficiency is higher than Nd∶YAG lasers.