Normally, granite magma is related to series of deposits and processes of tectonic geology. The studying results on the forming conditions create the basis for prospecting of mineral resources and other geological purposes. For studying on the forming conditions of Bµ Nµ granite we can use the ¹⁸O, ²H and Rb-Sr isotopic method.

According to the whole world calculation of dD, the rainy water participating in the formation of magmatic rocks in the SE Asia region is about -60+20⁰/_00. The result of dD_{H O} of the Bµ Nµ granite massif as -90⁰/₀₀ lies outside this level. It completely conforms with the oxygene isotope. The Bµ Nµ granite was formed at the temperature of 700⁰ C, and the "intermediate" water participated in the forming process of the rock. Cassiterite ore in Bµ Nµ was formed at the temperature of 380⁰C, and the "intermediate" water participated also in the process of ore formation.