Abstract: The first four circle neutron diffractometer in China is introduced. It ismainly used to study the crystal structure and the magnetic structure. Incidentwavelength is fixed at 1.69×10~(-10)m. The energy resolution of the spectrometer is4.7%. Maximum flux at sample is about 10~6 n/cm~2·s. Finally, the property of thespectrometer is measured and compared with other four circle diffractometer.