The potable water quality analyzer has the advantages of reliable performance,easy to carry and simple operation. Comparing with the traditional analyzers,it can avoid the errors produced as collecting samples from the site back to laboratory, during which the samples may change due to the environmental factors.The parameters should be the mean value((?))minus differ- ence value(R)which may control the analytical quality in order to provide the reliable and precise data.In addition,it has sug- gested the good measures that should be used in the field to analyze water quality in the condition of using this kind of analyzers.