  We introduce a simple method to estimate the system parameters in continuous
dynamical systems from the time series. In this method, we construct a modified
system by introducing some constants (controlling constants) into the given
(original) system. Then the system parameters and the controlling constants are
determined by solving a set of nonlinear simultaneous algebraic equations
obtained from the relation connecting original and modified systems. Finally,
the method is extended to find the form of the evolution equation of the system
itself. The major advantage of the method is that it needs only a minimal
number of time series data and is applicable to dynamical systems of any
dimension. The method also works extremely well even in the presence of noise
in the time series. This method is illustrated for the case of Lorenz system.
