The result of GPR investigation in west Jilin shows that the radar waveform of saline-alkali soil is different from that of tillable soil, and this can be used to distinguish tillable soil from saline-alkali soil. The extent of salinization can be determined according to the relativity of spectra. The saline-alkali accumulated part can be distinguished from the transitional part of saline-alkali soil according to instantaneous amplitude of GPR record. So the GPR integrated with geochemical means can interpret the salinization degree in depth rapidly, and can also be used in large-area surface survey.