ABSTRACT: The last few years Light Detection And Ranging (LIDAR) system is widely used for generating digital terrain models. LIDAR system outputs are more accurate, have higher density, are produced more rapidly, and with acquired less expensively. The developments of LIDAR systems have many of the elements that meet these properties. Airborne LIDAR has become commercially used for many environmental, engineering and civil applications, and can provide accurate data for topographic surfaces and non-terrain objects. Changes on urban area may be happened due to city development or effect of environmental hazards. LIDAR data for an urban area is used for producing two height images, before and after changing. Search technique is applied to detect the area of changes and the objects in this area. LIDAT data with rich spatial information is recommended to be the most suitable data for change detection applications on urban areas.