  The compatibility between the conformal symmetry and the closure of conformal
algebras is discussed on the nonlinear sigma model. The present approach, above
the basis of field redefinition employed in the Hamiltonian scheme, attempts
the method of quantisation with intuitive picture. As a general field theoretic
treatment, the consistency is ensured by means of the interesting features
which are observed in the historical studies for the gauge-invariant conformal
symmetry. The identification of conformal anomaly is also shown coincident with
the conventional one approached within the path-integral formulation.
