A purpose of this study is analyzing a human's controller to understand a mechanism of skill acquation processes for riding a unicycle. In order to analyze the controller, inputs which an operator gives to the unicycle and states of the unicycle are measured and a human-unicycle model as same as the experiment is derived. A weighting matrix to the state is obtained from the states, the inputs and the model solving inverse regulator problem. The human's controller for riding the unicycle is discussed by the obtained weighting matrix.