Fluid and silicate melt inclusions in quartz of two-feldspar pegmatite, tourmaline-quartz-albite near miarolitic assemblage and miarole of the Leskhozovskaya miarolitic pegmatite, SW Pamir, were studied in order to understand P-T-X parameters of pegmatite-forming medium at the magmatic-hydrothermal transition. Thermometric study showed that crystallization of the assemblages under interest occurred at about 600ºC and 2.8 Ц 3.8 kbar. Silicate melts of this stage is characteristically poor in SiO2 and enriched in B2O3, F and H2O. Aqueous fluid has borate-boric acid composition with extremely low Cl-content. It was established that silicate liquids of the transitional stage tend to accumulate K, Ta and Nb, while aqueous fluid concentrates Na, Li, W and Sb. Both liquids accumulate B and Cs almost equally.