Abstract: On condition of acid dissolving test samples, using ferriammonium sulfate as an indicator to test chloride ions content in concrete, the testing results are precise and titration end point is very obvious.Whereas using iron vitriol as an indicator according to Testing Code of Concrete for Port and Waterway Engineering(JTJ 270-98), it is found that the error is relatively large and titration end point is blur.Many experiments prove that adding organic solvent to testing liquor is very advantage, because it can avoid deposition developed from transforming.Which is more favorable for coloring of potassium chromate and improving testing precision in using water dissolving sample to test chloride ions, the concentration of sulfuric acid needs to dilute in view of practical situation.