Uniaxial oriented poly (ethylene chlorotrifluoroethylene) (ECTFE) fibers were prepared by the melt spinning method using ECTFE resin as the fiber-forming polymer. The crystal structures,thermal and mechanical properties and creep resistance of the prepared fibers were analyzed by X-ray diffraction (XRD),differential scanning calorimetry (DSC),mechanical and creep performance testing,etc. Results show that, the uniaxial oriented ECTFE fibers have favourable crystallization property. Their crystalline structures belong to hexagonal system,the degree of crystalline orientation is about 90%. The uniaxial oriented ECTFE fibers have excellent mechanical properties,thermostability,creep resistance and chemical corrosion resistance (such as acid,alkali,strong oxidizing reagents,organic reagents,etc).