Abstract: In this paper, the method for computing the complex transfer functions using the data of digital geomagnetic pulsation meter is described, and the result of data processing is given. From the figures we can see that during the normal period without earthquake occurrence, the transfer functions fluctuate around the stable values. As for earthquake with magnitude around 4,the transfer functions only with short periods have anomalous response. Because calculating a set of transfer functions requires data for only 1~3 days, it is possible to apply this method for searching the short-term and imminent anomalies.

Key words: Geomagnetic short-period variation, Complex transfer functions, Electric structure, Induced magnetic effect