Autonomous Underwater Vehicles (AUVs) are one of the key technologies for deep oceanic research. Several studies of AUVs have focused on thrust allocation limited in horizontal plane and designing control laws. Relationships between thrusters allocation and AUV s motion performance has not been clarified. If AUV s motion performance shifted to mission specialized by the relationships, we can expect oceanic research of more energy saving. In this paper, we propose an evaluation guideline for AUV s motion performance and a method of thrusters allocation based on proposed guideline. Additionally, we show numerical simulations which illustrate the effectiveness of the proposed method.