Abstract: Losses of the original marker result in a confusion of oil pipelines that can be recycled, which lead to huge security risks and great economic losses. In this paper, material identification tests of commonly used J55 and N80 oil tubes are conducted by eddy current method. Results show the size of response voltage is affected by lift-off, the direction of magnetic probe, the excitation frequency, etc. When magnetic probe is perpendicular to tubing, response voltage of two kinds of pipelines has good linear relationship with the 100~260 Hz sinusoidal excitation frequency, and response voltage of J55 is significantly different from that of N80 at the sinusoidal excitation frequency of 150 Hz. As a result, the recognition accuracy of these two kinds of pipeline is higher than 97%.