Abstract: From the theoretical conclusions of the symmetric and antisymmetric motion such as ‘the invariance of the symmetric motion' etc.if the initial motion were symmetric,in the course of time integration,a lot of results could be deduced for the spectral model,nanlely,1.The spectral coefficient associated with the antisymmetric motion would vanish at any instant.2.The forecast made by the global model would be the same as the forecast made by the hemispheric model over the same homisphere under certain condltlons.3.over any two regions which are geographically symmetric with respect to the equator,the motion would be symmetric to each other.And,these results have been verified by numerical experiments.In the casc of external forcing such as orography or heating,if its distribution and the initial motiou were both symmetric,then ‘the invariance of symmetric motion' would still hold.However,if the orography or heating were asymmetric,then the symmetry of the motion would much be reduced and the crossequatorial flow would occur By means of numerical experiments these also were verified.By using the above theoretical results as guidance,any new model designed may be tested and analysed.Then the judgment whether the dynamic frame of the model and its associated software are rational or not,can be made.