How to master the distribution of soil, especially the distribution of saline-alkali soil and the saline-alkali degree in the whole transformation area before exploration, how to test the result of transformation effectively are the problems that must be faced during the exploitation. This paper discusses the theory and process which resolve those problems with the methods of geophysics, and proves that those methods are feasible and effective. In order to make scientific and technical researches between different subjects, all those methods will be used in the national key programs of the Ninth Five-Year Plan: comprehensive management of saline-alkali land and agricultural sustainable development in the Songnen Plain.