This paper presents an approach for easily testable two-dimensional sequential arrays. This approach is an extension of GID(Group Identical and Different)- testability of combinational arrays in our previous work [8]. In a GID-testable two-dimensional array, the primary x and y outputs are organized into groups and every group has more than one output. GID- testability not only ensures that identical test responses can be obtained from every output in the same group when the array is fault free, but it also ensures at least one output has diRerent test responses from other outputs in a group when a cell in the array is faulty. Therefore, all faults can be detected under the assumption of a single faulty cell model. It is proved that an arbitrary two-dimensional sequential array is GID- testable if seven x-states and seven y-states are added to the original flovw table of the basic cell of the array.