Abstract: : An analysis of steady moisture and stress field in internal construction of composite material is performed by using F. E. M. and on the basis of reviewing the methods that are used to analyse the moisture absorption and moisture field in internal structure of composite material. It is assumed in computation that each ply which consists of laminated plate is transversly isotropic(lay in arbitrary direction) nine nodal points isoparametric elements with additional internal D. O. F. are applied. In this way, high accuracy can be acquired from computing without increasing additional pre-prepara-tion, A large number of examples have shown that the results satisfy the requirments in engineering if laminated plates of graphite composite material are dealt with according to one-dimensional moisture diffusion

Key words: composite material, steady, moisture field