In this study, carbon fiber/ polypropylene (PP) complex braiding yarn, with its different breaking strength, was prepared. It was designed by braiding polypropylene (PP) wrapped yarn and carbon fiber core yarn using eight and sixteen spindles braiding machines, with change of take-up gear number. Environmental factors, such as pH, temperature and time, were also changed to produce geo-grids with high strength, high modulus and better weather resistance. In order to make stable structure for complex braiding yarn, the heat treatment was also considered. Finally, geo-grids braiding by optimal treatment parameters were cut into single rib and junction specimens for tensile test.