Abstract: Based on experimental data of the samples,the characteristics of chemical components of pore water quality are analyzed,summed and classified.And its influence in Zhangji Well Field is analyzed.Some suggestion is put forward for the protection of the well field.The results show that:①Although complex,the common types of the chemical component of pore water are HCO₃-Ca·Mg or HCO₃-Ca;the following are the types with Na⁺;the next are the types with Cl^-.②Some components such as NH₄⁺,NO₂^-,NO₃^- and COD MN overtop the standard samples in different degree.③After the well field is exploited,pore water resources will become an important recharge source,and it has an important influence on the well field.So it must be considered in making a plan for the rational exploitation,scientific management and protection of resources in Zhangji Well Field.