Solving state feedback Hinfin control problem usually leads to controller gain too large. A effective method to solve the problem is simultaneously to introduce guaranteed cost control. The delay-dependent Hinfin -guaranteed cost control problem for linear systems with state delay is investigated. A delay-dependent condition for the existence of Hinfin and guaranteed cost memoryless state feedback controller is presented in terms of matrix inequality such that the resulting closed-loop system is asymptotically stable and guarantees Hinfin performance index, and an upper bound on the given cost function can be obtained. Furthermore, a design method of the optimal Hinfin-guaranteed cost controller is given against the constant initial value. Finally, a numerical example is provided to demonstrate the effectiveness and feasibility of the proposed results.