Although AR has a great possibility to apply to various field work support, only some studies can be used in practice. One of the problems is a tracking technique, which is a key technology of AR. It is, however, difficult to introduce conventional tracking techniques such as GPS method, ultrasonic method, magnetic sensor method, artificial marker method and markerless method into NPP fields because of the problems such as obstacles, surrounding metal objects, stability, expensive cost and narrow tracking area. In this study, therefore, the authors have improved artificial marker method, developed a long barcode marker which can be directly pasted on the pipes in plant fields, and then proposed a technique to realize fast, stable and less expensive tracking method.