A system and method for the high temperature in-situ determination of corrosion characteristics of a molten metal on an alloy under study is provided which takes place within an insulated furnace. A graphite crucible provided in the furnace contains an electrolyte formed from a molten salt of a metal halide. A reference electrode formed from the same metal as the electrolyte is immersed in the electrolyte solution in the graphite crucible. A beta-alumina crucible containing a molten metal is also provided within the furnace and preferably within the graphite crucible. A measuring electrode formed from the alloy under study is immersed in the molten metal. Standard electrochemical techniques are used to measure and analyze the electrochemical effects of corrosion of the molten metal on the alloy.