Peat soil comprises a large percentage of decayed vegetable matter from dead plants, which is decomposed in the presence of oxygen and micro-organisms. It is found in wetland bogs, moors, muskegs, pocosins, mires and peat swamp, and is characterized by high moisture content and high compressibility. It is also rich in humic acid and organic material. The physical and mechanical characteristics of peat soil are studied herein by conducting various laboratory tests based on the level of organic content of the peat. The results show that the greater the organic content in the peat soil, the higher the moisture content, porosity, compressibility and internal cohesion. Inversely, with higher organic content, the lower will be the density, consolidation coefficient and permeability. This is because the porous sponginess of organic material and the cohesive effect of the humic acid transform the structure of the peat.