In order to study the influence of aeration zone on the hydro -geochemistry changes in the process of precipitation recharge to groundwater, surface rock and soil samples of unsaturated zone in Yiyuan were collected and experimented by leaching and immersion. From the leaching test, these soluble anions, such as Cl - , SO4 2-, CO3 2-, NO2-, NO3- , etc, dissolved into the leaching solution firstly and metal ions K+ , Ca2+ , Mg2+ , Fe and so on in the solution began to increase subsequently. The initial pH value of leaching solution was alkaline, and then to neutral transition. The results of the soaking experiment show that after 5 minutes immerse, the chemical composition of different soak solution of rock and soil samples changed obviously. With the increase of soaking time, the content of ions like K+ , Na+ , Ca2 +, Mg2+ , Cl- , HCO3 - and the salt content in soaking solution increased in different degrees, but the ions of Cl -, SO4 2- changed differently in different rock and soil. Presumably know, a large number of materials have been leaching out and chemical properties of precipitation happened to greatly change while the process of groundwater recharged through the aeration zone.