Specialized mirrors are normally used as prefocusing and postfocusing optical elements in synchrotron radiation (SR) beam lines. These mirrors are used for extreme grazing incidence in the vacuum ultraviolet,X-ray regions. Mirrors are typically segments of far-off axis aspherics off-axis aspheres,such as cylinders,ellipsoids and toroid with radii of curvature from tens of millimeters to infinite. Surface figure or shape error for these mirrors is generally represented by root mean square (RMS) slope errors. Typical tolerances for these mirrors are 3 μrad for RMS slope error and 0.3 nm for RMS micro-roughness. Measuring the mirrors used in SR with high precision is very important. The long trace profiler (LTP) is used for metrology in SR besides optical interferometer. The LTP is used for testing surface slope error of SR optical elements in world and is not adopted in visible optics generally. Optical metrology methods used in SR are introduced in this paper.