In this paper, a system given in state space model has been controlled. To control this system, two different controller have been used, one of them is conventional PI controller. PI controllers are used industrial application enormously, but if the system doesn't have a mathematical model, PI controllers fail. Second controller type used in this paper is Fuzzy Logic Controllers and these controllers are very effective on systems which don't have any mathematical model. In this work three different membership functions 25 rules have been used and it is shown that using different membership functions has important effects on the system output.