Abstract: In this paper, optimal constant-stress accelerated degradation test plans are developed under the assumption that the degradation characteristic follows a Gamma processes. The test stress levels and the proportion of units allocated to each stress level are determined by D-criterion and V-criterion. The general equivalence theorem (GET) is used to verify that the optimized test plans are globally optimum. In addition, compromise test plans are also studied. Finally, an example is provided to illustrate the proposed method and a sensitivity analysis is conducted to investigate the robustness of optimal plans.