The identification of soil profile layers is the main research content of GPR investigation and also the basis job of time-domain signals extraction and quantitative inversion. In this study, pulseEKKO PRO GPR of 250 MHz central frequency was used to detect the soil profile layers of plots covered by different vegetation coverages or plots covered by same vegetation but with different growing conditions, and the results were compared the soil profile layers obtained by the method of digging profiles, and the response characteristics of electromagnetic wave signals to soil water, salinity and grain size composition were also analysed. The results showed that: 1) By observing GPR spectral images, soil profile variation with different vegetation coverages and growing conditions can be distinguished with errors mostly are less than 0.5 m. 2) Soil layer information in the depth of 0–1 m can be clearly distinguished with comprehensive analyses of soil profile spectral images and amplitude-time data with 0.1 m discriminating error of soil layering. 3) The effects of soil salinity on electromagnetic wave signals are very significant in this region.