Abstract: In this paper the parameters of an actual wind turbine system are estimated with Kalman filter algorithm and its aerodynamic performance is studied by means of parameter estimation.A 5-meter diameter wind turbine system and some methods for data acquisition are briefly descripted.In order to find out the statistical chara-cteristics of these signals the 7T08S signal processor is used,and some frequency spectrograms are obtained.In the second part of this paper,the model parametersare estimated.We did this with three methods.These three methods and their computer program running times are compared.