Abstract:According to the variational characteristics of physical variates in discrete for-mation model,we achieve physical variate description using Walsh function. The ar-ticle presents two definitions and four theorems,analyses Walsh function descrip-tions of 1-D,2-D and 3-D discrete formation models,and offers a description exam-ple of 1-D formation model. The theoretical and practical computation results show that Walsh function description can effectively reduce the described parameters,then very favour the solution of discrete inverse problems on condition that physical variates of formation are inner-layer constants or inner-block constants.