Abstract: The frequency tuning of LD-pumped non-planar ring Nd:YAG resonator laser is studied.The output power of the 1319nm single frequency laser is tuned broadly in 14GHz by temperature control.Further more,the main cause of single-frequency laser's intensity noise is studied.The intensity noise is measured and the result for an active feedback loop that suppresses the relaxation oscillation noise is presented.The intensity noise is suppressed 30dB at the central frequency of relaxation oscillation,measurement precision is improved.