Abstract: It is thought impossible that Sr²⁺, Ba²⁺ and SO₄^2- can coexist in inorganic chemical analysis on water. However, it is of common occurrence that Sr²⁺and SO₄^2- can be detected simultaneously in highly saliniferous formation water, which is caused by the salt effect in it. Therefore, the analysis of highly saliniferous formation water should be done including the detection of the content of Sr²⁺, Ba²⁺ and SO₄^2- simultaneously.