We describe a Q-switched Er:GdVO4 laser resonantly pumped by a MgO-doped periodically poled LiNbO3 optical parametric oscillator (MgO:PPLN OPO) at 1 536 nm.In continuous-wave lasing,the maximum output power is 1.14 W with an incident pump power of 4.7 W and a slope efficiency of 27%.In Q-switched operation,1.1 mJ of output pulse energy is achieved at 200 Hz.The upper-state lifetime at different pulse repetition frequencies is also calculated.