Abstract: This paper reviews present development of pig tracing and positioning techniques. Advantages and disadvantages of five conventional tracing and positioning techniques, including radioisotope, mechanical, acoustic, pressure and magnetic method, are analyzed. Among these methods, electric-magnetic pulse and pressure methods are considered as the best methods with highest stability and maturity. This paper proposes the development of remote tracing and positioning techniques based on these two methods to replace artificial judgment by intellectual judgment. Unfortunately, the techniques may not be used to perform on-line tracing in real time. Accordingly, the on-line tracing and positioning technique based on principles of optical fiber vibration is proposed to achieve on-line tracing in real time through whole-process monitoring on location of the pig. With no dependence on any external conditions except the optical fiber, the technique represents a key development trend of pig tracing and positioning techniques in the future.