In electrochemical measurements, reference electrode (RE) is used to provide a standard for the potential on working electrode. Reference electrode should have three major capabilities: reversibility, reproducibility and stability. In the molten salt field, a thermodynamic RE is widely accepted to be an accurate standard. Since the great thermal properties and great ion conductivity of alumina; and low vapor pressure of NiCl2, the alumina tube enclosed NiCl2/Ni RE is designed for high temperature long-term usage in chloride salt. RE impedance measurement to check RE quality, CV measurement to check RE reversibility, and CP measurement to check RE potential stability were conducted at three temperatures (600 oC, 700 oC, and 800 oC) in a 10 days period. The SEM image scan provided information of the ion conduct path in alumina. The results will encourage the high-temperature electrochemical society.