A study of orthopyroxene samples from eastern Hebei shows that orthopyroxenes were formed by metamorphism of early and late stages.The variation in chemical cmposition of orthopyroxene is mainly related to conditons of metamorphism and types of coexistent minerals, and also controlled by the composition of the protolith.Geothermometer-geobarometer calculations indicate t=817-937℃，P=0.99-1.11GPa at the early stage metamorphism,and t=747-834.and t=747一834℃，p=0.95GPa at the latestage.