Recycled Polyester Fiber can be applied to clothing. Polyethylene terephthalate fibrics have some problems in moisture absorption and quick drying because PET is hydrophobic materials. So we studied polyoxyethylene diamine modified PET and its thermal properties, surface resistance, rubbing voltage, water absorption rate and water evaporation rate. The more content of polyoxyetylene diamine in modified PET, the lower melting point and surface resistance, even can get a antistatic materials; rubbing voltage decrease from 200-800 V to below 50 V; water absorption rate increase beyond doubled and water evaporation rate can reach 65.9%. Therefore, polyoxyethylene diamine is a very effectively modified hydrophilic monomer.