Abstract: A local refinement method of three dimensional tetrahedron elements is presented in this paper. It is the extension of Lo ¨hner's mesh enrichment method for two dimensional triangular grid. Three steps are included in the whole process. First, a certain number of elements which need enrichment is defined according to the remeshing parameters. Those elements are called initial enrichment elements, which will be subdivided into eight small tetrahedra by introducing the midpoints of each side as new verte...