Abstract: A laboratory system of low power(1 kW class)arcjet engine is described.It consists of a power supply and ignition system,propellant feeding system,engine body and some measurment devices. The performances described were acquired for different constrictor diameters(0 6～1 mm),mass flow rates(20～100 mg/s)and voltages(80～150 V)of power supply with Nitrogen and Argon.All of the tests were conducted in a 1 6 m long and 1 m in diameter vacuum chamber.