We rePOrt Study on a Nd: YLF laser side-pumped by a quasi CW 60 W laserdiode-array. The laser provided 4.4 mJ output energy at 1.047 μm with repetition rate of 30 Hz. Which gives an optical efficiency of 18.3% and slope efficiency of 24.4 %.On acousto-ootic and electro-optic Q-switched operation, pulse energy of 2.2 mJ was obtained with pulse widths of 50 ns and 30 ns respectively. The optimal output transmission at free running was revealed in experiments. Some parameters were compared with those of Nd:YAG lasers.