Laser induced fluorescence (LIF) has good qualities of high sensitivety, fast detecting speed, automatization and noninvasive measure in the water pollution detection. This method drew much attention in the environment monitoring area, and it had some applications. The 355nm third harmonic Nd: YAG solid laser was used for the excite source, and photon counting system was used for the fluorescence spectrum detection system. Using this system, laser induced fluorescence experiments were done. Some discussions...