The problem of estimating state of dynamical system from only input and
output measurement remain always an important field in the system theory. In fact,
observers play a key roles during monitoring of process, a there are shown an
essential component in many control application such as output regulation. Ahhough
the theories and applications for linear systems are well developed, development of
observers for nonlinear system still provides an open area for research. Quadruple
tank system and its mathematical model with typical parameters value will be
collected from the reflected real system of quadruple tank. Dynamics simulation will
be performed and through the MATLAB® enhancement. Various input changes take
part. The result of the simulation will be analyzed and reported
