On August 28, 2011, a landslide occurred at kilometer 53 on Highway 1095 (Mae Ma Lai - Poi) with light rainfall jar the average of 30 mm/day in rainy season. The relationships between clay mineralogy and landslide-inducing behavior of the soils derived from weathered granitic rocks were carried out to better understand the nature of landslide. Clay mineralogy determination was analyzed by X-rays diffraction analysis. In addition, physical properties of the soils including soil permeability, grain-size distribution, Atterberg's limits, and direct shear strength were also determined to classify the pattern of landslide. As a result, shallow with debris slides was classified. Low permeability of well-graded sands with clays was recognized in the landslide and non-landslide areas. The liquid limit of 19% and 28% with the plastic index ranged of 6% to 16% were identified in landslide areas, where those of non-landslide areas are of 25%-34% for the liquid limit and 8%-17% for the plastic index.