A mobile robot with various types of sensors via ubiquitous networks is introduced. We designed a mobile robot composed of TCP/IP network, wireless camera and several sensors in an environment, and show object avoiding and tracking methods necessary for providing diverse services desired by the people. To avoid obstacles(objects), active sensors such as infrared rays sensors and supersonic waves sensors are employed together and measures the range in real time between the obstacles and the robot. We focus on how to track a object well because it gives robots the ability of working for human. This paper suggests effective visual tracking system for moving objects with specified color and motion information. The proposed tracking system includes the object extraction and definition process which uses color transformation and AWUPC computation to decide the existence of moving object. Active contour information and shape energy function are used to exactly tract the objects with shape ch...