We investigated the chemical kinetics of NiCl 2 reduction to apply to the synthesis of nickel nanoparticles in a tubular furnace reactor. The conversion of NiCl 2 increased monotonically with reaction temperature up to 99% at 950°C, and in turn, the rate constant of the reaction increased from 78 to 286 with an increase in the temperature from 800 to 950°C. The reaction rate was estimated to be the first order with respect to chloride concentration, and the rate constant obeyed the Arrhenius law, of which the activation energy and pre-exponential factor were 103.79kJ/mol and 7.34×10 6 min −1 , respectively. Taking advantage of the kinetics, we synthesized crystalline nickel nanoparticles with average primary particle size ranging from 31 to 106nm by systematically controlling the reactor temperature and chloride concentration.