[Background] As typical and representative periglacial landforms in the Mt. Laotudingzi in multimodal (25%). The sedimentary environment was categorized as fluvial according to the calculation by Sahu discriminant. Considering the grain-size characteristic parameter, sediment-size frequency distribution and the asymmetrical sedimentary features in southern and northern slope, it was preliminarily inferred that the incipient sediment source should be including the weathered material of local rock fragments formed by frost weathering and the sand long-distance deposit by wind from the area of Yellow Sea and Bohai Sea in late glacial; and the multi-component removed and deposited by periglacial stream during a long process, and settled on the surface ground. The fractal dimension of grain size was between 2.11 to 2.39 and average on about 2.28, taking the ratio of clay and fine silt into consideration, it could be deduced that the water dynamics here was not strong.  [Methods] In order to fill the blank of the research on this area and provide the reference data for the soil and water conservation specialist or forestry specialist, based on the investigation and fieldwork, the undisturbed soil samples were returned and pretreated, the grain size characteristics of the overlying soil in 48 sample plots were analyzed. [Results] The most of the soil particles were fine (average on about-value is 6.45), and the soil texture was mainly dominated by clayey silt. Additionally, the soil texture also had other presentation by consisting of silt or sandy silt that was rarely discovered. The soil of the study area was mainly positive skew distribution (about 58%), and the sorting feature of grain size was “Not good"(I about 1.89), as for leptokurtosis, most of the soil samples were showed by “Very narrow''(83%). The frequency curves of sediment-size distribution of48 samples presented in 3 forms by test data showing: unimodal (25%), bimodal (50%) and multimodal (25%). The sedimentary environment was categorized as fluvial according to the calculation by Sahu discriminant. Considering the grain-size characteristic parameter, sediment-size frequency distribution and the asymmetrical sedimentary features in southern and northern slope, it was preliminarily inferred that the incipient sediment source should be including the weathered material of local rock fragments formed by frost weathering and the sand long-distance deposit by wind from the area of Yellow Sea and Bohai Sea in late glacial; and the mult-component removed and deposited by periglacial stream during a long process, and settled on the surface ground. The fractal dimension of grain size was between 2.11 to 2.39 and average on about 2.28, taking the ratio of clay and fine silt into consideration, it could be deduced that the water dynamics here was not strong. [Conclusions] And the fractal dimension, together with the environmentally sensitive grain size component, reflected that the better the land surface vegetation covered, the more significant the depletion and suppression of water erosion were. The characteristic of grain size here indicated that the intensity of water erosion was low and vegetation coverage played the vital role in the the water and soil conversation.