This article proposes the new concept called Similar Coefficient of cluster for discrete elements (SCD). SCD is not only used as a criterion for establishing cluster in hierarchical and non-hierarchical approaches but is also considered as a measure to compare the goodness degree of built clusters. Based on SCD, we also propose the algorithm for determining the suitable number of clusters, the algorithm for fuzzy clustering and the algorithm to build clusters with given SCD. The numerical examples demonstrate suitability and advantages of the proposed criterion in clustering.