The electromagnetic method seems more effective and easy to handle thanother electric survey techniques in detecting such underground conductors asmetallic pipes and cables. The method of using nonreference-line imagin-ary component instrument (DDW-1) and adopting orthogonal circuit device toobserve imaginary components of magnetic field is especially suitable for dete-cting metallic conductors in cities (even in urban districts). This is becausethe system only has a narrow band receiver and is not connected to ground,and the observations have little to do with the transceiving distance. General-ly speaking, the induced current caused by metallic pipes and cables in theelectromagnetic field can be approximately regarded as line current, so the in-terpretation of the data is rather simple. The present paper gives some out-comes obtained in urban and suburban areas of Beijing.