First, the geotextiles function and role 1. Isolation namely the use of geotextile materials with different physical properties (particle size distribution, consistency and density, etc.) (such as soil and sand, sand and gravel, soil and concrete ) isolation. So between two or more materials is not lost, not mixed, maintaining the overall structure and function of materials, so that the load bearing capacity of structures strengthened. 2. When the water filtered by the soil flows into the coarse material fines soil, the use of geotextile good air permeability and water permeability, water flow through. And the effective closure of the soil particles, sand, small stones, so as to maintain a stable water and soil engineering. 3. drainage geotextile is good water permeable material, it can be formed in the soil drainage channels inside the body, the internal structure of the soil excess liquid and gas emissions. 4. Enhanced use of geotextile reinforcement tensile strength of the soil and resistance to deformation, increase the stability of the building structure in order to improve soil quality. 5. Protective effective stress will focus on proliferation, transfer, or decomposition, to prevent soil damage by external force while. 6. Closed geotextile and other materials (asphalt, plastic film) with the formation of impermeable barrier in soil. (Mainly for road resurfacing, patching, etc.). First, the application of geotextile geotextile due more than six functions, it is widely used in railways, highways, sports stadiums, dams, hydraulic construction, tunnel, along the beach.