In order to study the differences of hydrochemical characteristics between Laolongdong ground river exist(G3)and epikarst springs(G1, G2)and its impact factors, the statistical approach was applied to analyze the monthly data of groundwater hydrochemistry in 2012. The results showed that the chemical composition of groundwater is mainly composed of Ca²⁺, Mg²⁺, HCO^-₃ and SO^2-₄, and the main type of hydrochemistry is Ca-HCO₃. The concentration variation coefficient of Ca²⁺, Mg²⁺, HCO^-₃ is small, which mainly come from carbonate rock dissolution and mainly be dissolved in limestone. Sulfuric acid and nitric acid are involved in the dissolution of carbonate rocks, in which sulphuric acid has greater influence on dissolution of carbonate rocks. However, affected by factors such as agricultural fertilization, livestock manure, enterprise waste water and domestic sewage, the concentration variation coefficients of SO^2-₄, PO^3-₄, Na⁺, K⁺, Cl^- and NO^-₃ in groundwater are larger, in which the concentration of SO^2-₄, PO^3-₄, Na⁺, K⁺, Cl^- in underground river were higher than that in episkarst springs, but NO^-₃ concentration in underground river was lower than that in episkarst springs.