Strain controlled uniaxial tensile and compressive tests of rolled compacted concrete ~RCC! are conducted to establish the constitutive relationship of RCC. Complete stress-strain constitutive curves including strain-softening behavior of the material have been obtained. To satisfy the test requirements for obtaining the strain-softening behavior of the material, the stability conditions on specimen parameters and machine rigidity are described based on the concept of strain localization. By using test results of RCC, a 200-m high RCC gravity dam, Longtan Dam, is analyzed for earthquake resistance using the procedure of nonlinear fracture mechanics and the compression-shear failure mechanism for concrete. A safety evaluation of the dam's ability to resist the design earthquake under different reservoir elevations is performed.