Interest to Gallium Phosphide crystals is connected with outlook for creation of smart sensitive device for optoelectronics, for photo- and LED and for others semiconductor devices. The use of a new technology based on different types of laser treatment of materials the wide possibilities for practical application and for modern device creation reveals. This technology is followed by radiation defect generation due to this the defect state of crystals can be changed to required direction. Variations of defect structure state of crystals by means of laser irradiation action is resolved to improve the types of produced device and to extend the region of its application, it is very important. In this work the investigations of impulse laser irradiation action on the photoluminescence (PL) of GaP single crystals doped by nitrogen (C=0,2 and 0,02 N) as well as long-term ordered at room temperature ( more 50 years) are presented [1]. The photoluminescence was excited by YAG:Nd3+( λвоз =355нм). Duration of laser action was equal to 20 minutes. The PL spectra were studied at room temperature in a wavelength range of 350-1000 nm, The influence of laser radiation on the mechanical properties was estimated by change of microhardness value. The PL spectra of GaP crystas at 300K two maxima at 2,7 and 2,2 eV show. All the sampless have the same band shape, which may indicate a common nature of radiactive transitions from conductig band to valence one. The shape of PL curve in 2,7eV region involves the summary (total) spectrum of severel peaks and in some cases it is shifted to more wivelength 2,8eV region. The wavelength region of this photoluminescence band is rather determined by emission on defects, the generation of which follows the process of deplacement of phosphor by oxygen whithin the GaP structure. It is also possible that, structure change of GaP crystals during long-term ordering at room temperature causes the 2,7 eV band (shift) displacement to more wavelength region of spectrum in comparison with data of initial GaP samples ( undoped and disordered). It is known, that undoped GaP crystals exhibit (show) the photoluminescence characterizing by weak intensity. Investigated in this work GaP crystals contained oxigen as impurity, however, the oxigen existence did not practically change the position of 2,2 eV peak, but its intensity essentually increase. Photoluminescence arising at impulse laser radiation action is assumed to arise from relaxation of point defecds between levels of suppressed zone. Against common photoluminescence decrease in irradiated GaP single crystals the peak of PL connected with direct transitions (2,7eV) from conducting bank to valence in comparison with indirect ones (2,2eV) increases. Has been established that position and height of PL spectrum peaks are not determined by change of microhardness value but are dependent on structure state of doped and long-term ordered GaP crystals. [1] S.L. Pyshkin, J. Ballato, G. Chumanov, et al. in Abstracts, Chisinau, Moldova, 54 (2008)