H−matrices play an important role in the theory and applications of Numerical Linear Algebra. So, it is very useful to know whether a given matrix A ∈ C n,n , usually the coefficient of a complex linear system of algebraic equations or of a Linear Complementarity Problem (A ∈ R n,n , with a ii > 0 for i = 1, 2, . . . , n in this case), is an H−matrix; then, most of the classical iterative methods for the solution of the problem at hand converge. In recent years the set of H−matrices has been extended to what is now known as the set of General H−matrices, and a partition of this set in three different classes has been made. The main objective of this work is to develop an algorithm that will determine the H−matrix character and will identify the class to which a given matrix A ∈ C n,n belongs; in addition, some results on the classes of general H−matrices and a partition of the non-H−matrix set are presented.