We report read out test result of inorganic scintillator; Ce:LiCaAlF 6 single crystal for neutron detection at spallation neutron source. The Ce:LiCaAlF6 crystal is tested in J-PARC spallation neutron source, which is background gamma-ray energy is higher than those from Co-60. Different size and thickness of crystal is tested and with 2 mm cube crystal, we managed to discriminate gamma ray with pulse height. Short light decay time of Ce:LiCaAlF6 would be an also great characteristic for high intensity neutron source. Ce:LiCAF shows excellent characteristics in the detection efficiency and gamma-ray discrimination compared with other conventional scintillators, such as Li-Glass and Li:ZnS scintillators. Especially, excellent pulse height discrimination of neutrons from gamma rays and very short decay time are very promising for a new field of high counting rate neutron detection with scintillators.