Abstract: The micro-robotic system, Tubot II, is developed for automatic inspection of flaws inside 20mm pipelines made of non-magnetic metals. It is composed of a micro-locomotion mechanism, a two-layer computer control system with a user-friendly graphics interface, an eddy-current sensor, a signal-analyzing instrument and a tape recorder. This paper presents the system design, the key technological components and the performance experiment of the robot. When commercialized, the robotic system could have potential applications in the regular inspection of pipelines, which will be widely used in nuclear power plants, chemical factories, refrigeration industry, and utility engineering.