Abstract: A sequence instruction display system used with a programmable sequence controller for displaying a desired sequence instruction and the on-off state of the input or output element corresponding thereto. A data processor stores the address data of an input element in an input address register when the on-off state thereof and an input instruction corresponding thereto are displayed. The data processor, when a signal is applied thereto, searches a program storage area for an output instruction having the address data which is stored in the input address register and further searches for an input instruction which concerns the energization of the output element corresponding to the output instruction to thereby enable the operator to find a desired sequence instruction by a simple manipulation.