More and more researchers took interests in FRP materials in civil engineering for their light weight, high strength and excellent durability performance. But common FRP rebars or plates used for reinforcing or strengthening in civil engineering are mostly made by fiber reinforced thermosetting polymer (FRSP) materials. While FRSP can not be reshaped so that many of the special shapes as bending rebar or hoop rebar cannot be easily obtained and handled at site. So, here we developed and fabricated Glass Fiber Reinforced Polypropylene (GFRPP) according to Fiber Reinforced Thermoplastic Polymer (FRTP) systems. This paper is focused on the experimental and theorial studies on the corrosion resistance of GFRPP rebar in alkali, acid and salt solution at different temperature. According to the corrosion experimental data, some durability life prediction would be concluded through FHWA method, and which may be valuable to a deeper understanding on the durability of GFRPP rebars. The results show that these kinds of GFRTP rebars have good resistance in acid and salt solution, and their mechanical properties can remain well, while bad resistance in alkali solution. As can be regarded that these FRTP rebars can be a vital support of common FRSP materials and which would play an important part in civil engineering in the future.