This report describes the design, fabrication, and testing of a new type of multiaxial testing device for geologic materials. The new testing device reduces the effects of boundary conditions in determining the physical properties or constitutive relations for elastic anisotropic material, and the development of a procedure to obtain anisotropic shear compliance values are contained in chapter 2. A literature survey and discussion of past work in multiaxial testing of geologic materials are found in chapter 3. In chapter 4 a detailed look is taken at the boundary conditions associated with the cubical test. Based on conclusions reached in chapter 4, a new type of multiaxial test device was designed and built as described in chapter 5. In chapter 6 results of experimental studies to determine the effectiveness of this new device are presented. Chapter 7 contains the results of the application of the new device to the determination of the constitutive relations of an actual material. Chapter 8 gives the summary and conclusions and makes recommendations.