Abstract: In this paper, the law of many years and annual variation dynamic characteristics of the groundwater level in Yutian well since 1983 are analyzed. Using the rainfall of different time interval, correlation analysis on the rainfall data and the annual extreme value and rise or fall ex tent of the groundwater level is made. The result show s that the groundwater level state was basically controlled by rainfall, it doesn't match the rainfall in some years, when the moderately strong earthquake occurred. Therefore it i s of precursory significance, when it doesn't match the secular variation and rainfall, the law will be changed for annual-variation of a year dimension in groundwater level state.

Key words: Water level, Many years'dynamics;, Annual variation dynamics, Rainfall, Correlation analysis