Abstract: Comparing with Kaufmann ion thrusters, ECR(Electron Cyclotron Resonance)ion thrusters have neither electrode erosion nor pollution, as well as low discharge pressure, high plasma density, and high energy transfer efficiency. ECR ion thruster has drawn much attention in low power electric propulsion. Foreign countries(mainly Japan)have great progress in low power ECR ion thrusters in diameter from 1 cm to 10 cm, and got amazing achievement, such as getting samples back from a asteroid. However, chinese ECR ion thrusters are still some lab models, whose performance and engineering mature level are lower than foreign ones. It is advised that more research focus on magnetic field topology, grids with variable-holes in carbon-carbon composite material.