Vibration isolation system is a prerequisite to achieve high resolution picture using scanning tunnel microscope (STM). The principle of spring damping isolation, staked flat-elastomer isolation, pneumatic isolation, and sandbox damping isolation is introduced. The relationship between resonant frequency of the isolation and the effect is presented. The four resonant frequencies are calculated through Finite Element Analysis (FEA). The four vibration isolations is designed and optimized according to the analysis. The experimental results show that spring damping isolation has the best effect and a transfer ratio of
10<sup>-6</sup>(120dB) can be obtained.