We demonstrated a diode-pumped Nd:YAG laser with a plano-concave resonator. When the pump power is 1.57 W, the output power of 1123-nm laser is 132 mW at the temperature of 20 oC, and the power change is less than 2% in an hour. A periodicallypoled LiNbO3 (PPLN) was used as outer cavity frequency-doubling crystal and 561-nm laser was observed.