This paper presents a Takagi-Sugeno (T-S) fuzzy-model-based controller for the tracking control of autonomous underwater vehicles (AUVs) on a vertical plane. Through sector nonlinearity methodology, the nonlinear AUV system on a vertical plane is modeled as T-S fuzzy model. Using the line of sight (LOS) method, the tracking control problem is converted into the stabilization one for the error model between the given nonlinear AUV and the waypoints. Lyapunov function is used to derive the stabilization conditions for the error model in the format of linear matrix inequalities (LMIs). An example is provided to illustrate the effectiveness of the proposed methodology.