A constrained linear optimal control for a lowpower industrial gas turbine based on input-output linearization is proposed in this paper. It uses a nonlinear state space model of the gas turbine in input-affine form based on first engineering principles. According to the control aims the nonlinear model is inputoutput linearized and an LQ servo controller is developed for the linearized model. We have some additional constraints on the state and input variables of the closed-loop plant fed back by the LQ servo controller. These constraints can be kept in a simple way designing an MPT-controller. The complete control structure is investigated by simulation studies.