Throughout the present paper, K denotes a complete, non-trivially valued, ultrametric (or nonarchimedean) field. Sequences, infinite series and infinite matrices have their entries in K. The sequence spaces m?, c?, c?0 were introduced in K earlier by the author in [8-10] and some studies were made. The purpose of the present paper is to characterize the matrix classes (c?0, c? 0), (c?0,m?), (c?0, c?) and (c?, c?0).