Two photon laser induced fluorescence spectrum (TP LIF) of NO in the wavelength range 220～350 nm is obtained by using optical parameter generator and amplifier pumped by Nd∶YAG laser as excitation source. A few stronger band can be attributed to A 2Σ(v′=0)→X 2Π(v″=1～8) transition. Some molecule constants about NO in the ground state are deduced by the spectrum. The Frank Condon factor and relative spectrum intensity are calculated. Compared with the results of experiment they are in accordance basically and a little difference is discussed. All of these can provide an important reference for monitoring of NO by the technique of laser induced fluorescence.