利用转换函数的方法分析了武汉台1990年1月至2000年12月地磁短周期T=9～200min的转换函数A、B的模|A|、|B|及总方差δZ的月变化，并对武汉台周围500km范围内的4次ΜS4.0以上地震进行了分析。分析结果表明：不同周期的转换函数A、B以及总方差δZ在震前有明显变化。
The changes of short period magnetic conversion function A and B (T=9-200min) from 1990 to 2000 were analyzed by the method of conversion function, and also compared with 4 earthquakes (ΜS>4.0) within 500Km of the areas around Wuhan. The result indicated that there were the obvious changes at different period conversion function A and B before the earthquakes occurred.
