Abstract: Abstract：We may deduce the stress field orientation in the fault belt by an integrated analysis of the calcite petrofabric in tectonite of a fault belt and deduce the orientation of the paleostress using the C (compressive)-T (tensile) stress diagram of calcite with e-twins. The methods have been applied by many geologists in the practice. In the Baiyangping east ore district of Yunnan, the Huachangshan and Shuimofang faults are the principal ore-controlling structures. The petrofabric diagrams of calcite optic axis and e-twin poles both show c-axis pole maxima and girdles, indicating that the compressive stress in the c-axis direction causes gliding along the ab plane. In the C-T stress system, the principal compressive stress is oriented in a SE-NW direction and the principal tensile stress is oriented in a NE-SW direction, and the sinistral motion predominates for the Huachangshan and Shuimofang faults; the SE block of the Huachangshan fault is thrust in a NW direction, while the Shuimofang fault is thrust antithetically from NW to SE. These coincide with the macroscopic structural analysis in the field.