It is a unique millimeter wave radio telescope with aperture of 13.7M in China and advanced one in the world as well，which has a R-C optical system with focal ratio=0.37，main plate accuracy of 0.13mm(RMS)，shortest working wavelength of 2.6mm and pointing accuracy of 3 arcseconds for azimuth-altitude as well as tracking accuracy of 3 arcseconds for azimuth-altitude。The first one located at DeLinha observation base of Purple Mountain Observatory in Qinghai province while the second one at headquarters of space in Finland。