In order to accurately reflect the condition of groundwater quality,this paper introduced the basic principle of three assessment methods including F-value , Nemero index and fuzzy comprehensive evaluation method.Taking six types of groundwater sample collected from dry season of Beijing in 2013 for example,it carried out assessment and analysis.The results show that F value method uses simple, results are intuitively displayed and widely applied, but it can cause some discontinuity and lack of class Ⅲ water. The calculation method of Nemero index is simple, but it extremely emphasizes on the largest pollution factor, and there is no accurate basis for groundwater quality category. Although the calculation process of fuzzy comprehensive evaluation method is complex, but the result is more accurate. The comparison and analysis of three methods can provide technical guidance for the rational choice of evaluation methods of groundwater in practical project.