The possibility of growing of AlN, GaN and InN crystals at high pressure of N has been analysed. Thermodynamical properties and its consequences for crystals growth have been shortly discussed on the basis of the results of high pressure experiments up to 20 kbar. At this pressure range the best results have been obtained for GaN. AlN requires higher temperatures to increase the solubility of N in the liquid Al. For InN the pressure of 20 kbar is not sufficient for effective crystallization. 21 refs, 6 figs, 1 tab.