To search for the obvious noise of geomagnetic interference occurred near the Beijing observatory round about March of 1988, we set up 8 sites in Sujiatuo-Wolonggang area. The special experimental observation of the geomagnetic interference noise was carried out with the model G-816 and G-826 proton precession magnetometers. The results show that the geomagnetic interference noise mainly originated from the electromagnetic interference in the Xiangshan region, and subsequently from the subway in the Beijing City. The geomagnetic inter-ference noise occurred at 06h-23h (the Beijing time)each day. Its dominant spectrum is at short-period(T=2-4m). The method of the observation and research in this paper has practical application value for monitoring the environmental condition of geomagnetic observatory (site) and for correcting the contaminated data of geomagnetic field.