In this paper, we present a method of determining the parameters of a dynamic system using state estimate filter. State estimate filters such as Extended Kalman filter and the Unscented Kalman filter are widely used to estimate the status in robot and GPS navigation systems. However, in dynamic systems, determining parameters is difficult because many kinds of the dynamic systems have the properties like a non-linearity and complexity. The work we have done is that the status and parameters are simultaneously estimated to decide the parameter value based on the measurement data set of the system. The works were applied to a coupled tank. The mentioned system was modeled and then setup for computer simulations and experimental purposes to test the performance of the estimation process. Copyright Â© 2013 SERSC.