A method for editing continual vertical line of visual programming language includes following steps: entering an editing mode; selecting a source node as a current node from a serial-parallel graphic where the source node is an endpoint of one of a plurality of normal blocks in the graphic; calculating and displaying one or more candidate nodes around current node; connecting the current node to any one of the candidate nodes for converting the connected candidate node into a connected node; setting the connected node as the current node for continually calculating, displaying, connecting to one or more candidate nodes before exiting the editing mode; generating a continual vertical line according to the source node and the one or more connected nodes when exiting the editing mode; modifying the serial-parallel relationship among the plurality of normal blocks in the graphic and updating the graphic according to the continual vertical line.