The chloride content in various salt-affected soils in Jiangsu,Xinjiang,Henan and Gansu provinces are determined by three methods,which are the automatic differential potentiometric titration,Mohr method and anticipated end point potentiometric titration.The advantages of the application of an automatic differential potentiometric titrator for the determination of chloride in salt-affected soils are as follows:1.The result of determination is not affected by the change in Eo' of electrode,slope of the titration curve and the variation in ionic strength of soil solution.2.The method is rapid and accurate.It is not necessary to anticipate and check the end point potential.The results of determination have good reproducibility.3.This instrument can also be used in other fields,such as complexometric titration,oxidation-reduction titration,acid-base titration etc.