Theory and method of determination of elastic parameters of wood are here presented, where the wood was supposed to be in the ideal mechanical model. It is pointed out that the moisture content coefficients of the elastic parameters have the same property of symmetry as the parameters. The tesults of the determination of the elastic patameters of Manchurian ash (Fraxinus mandshurica) wood proved that the supposition of the ideal mechanical model is right and that electrical measuring method is a reliable means of determination.