The chloride ion contained in reinforced concrete seriously corrodes the steel surface and damages concrete, resulting in inferior reinforced concrete that strength seriously compromises the entire structure’s safety. Consequently, the examination of chloride ions contained in reinforced concrete becomes an important part of a complete quality control procedure. To effectively check the concentration of chloride ions in concrete, the evaluation process should be accurate and precise. Laboratory data ob- tained using existing evaluation methods for the examination of chloride ion are not sufficiently objective to yield reliable results with accuracy and consistency for each sample. An evaluation algorithm with capability to define indices of precision degree (Ep) and accuracy degree (Ea) is presented in this paper. The authors established a statistically reliable index of unbiased estimators and equations to critically examine the laboratory methods’ precision, accuracy degrees and application value for measuring chlorine ion concentration in reinforced concrete. The chloride ion contained in reinforced concrete seriously corrodes the steel surface and damage concrete, resulting in inferior reinforced concrete that strength seriously compromises the entire structure's safety. procedure. To effectively check the concentration of chloride ions in concrete, the evaluation process should be accurate and precise. Laboratory data ob- tained using existing evaluation methods for the examination of chloride ion are not yet objective to yield reliable results with accuracy and consistency for each sample. An evaluation algorithm with capability to define indices of precision degree (Ep) and accuracy degree (Ea) is presented in this paper. The authors established a severe reliable index of unbiased estimators and equations to critically examine the laboratory methods' precision, accuracy degre es and application value for measuring chlorine ion concentration in reinforced concrete.