The Archean granulite rocks in Inner Mongolia occur mainly in Dining and Wulashan Groups which extend from $adamengou near $aotou in the west to Jining- Xinghe area in the east, roughly in E-W direction. The main rock-forming mineral is pyoxene widely distributed in the granulitc rocks. Integrated studies indicate that the orthopyroxene there is commonly rich in iTOn; that the variation in iron content of the mineral is in direct correlation with that of the rock, That the FeO,Mgt and Ca0 contents of elinopyroxene vary in a rather small range and that the Mg0 content of clinopyroxene is similar to that of orthopyroxene, both controlled by the components of the rocks. The two pyroxene in this paper belongs to the equilibriumassociated relation. The metamorphic temperatures obtained for the’two-pyroxene pair are 800-900 C. In the light of rock types and paragenetic association of the minerals it is inferred by calculation that the pressure is between(7-10)× lO8Pa, suggesting that the granulite belongs to the medium pressure phase.