  We study correlation functions of parafermionic currents and disorder fields
in the Z(N) symmetric conformal field theory perturbed by the first thermal
operator. Following the ideas of Al. Zamolodchikov, we develop for the
correlation functions the conformal perturbation theory at small scales and the
form factors spectral decomposition at large ones. For all N there is an
agreement between the data at the intermediate distances. We consider the
problems arising in the description of the space of scaling fields in perturbed
models, such as null vector relations, equations of motion and a consistent
treatment of fields related by a resonance condition.
