DYQ4 series liquid resistor starter is a new starter prepared for improving the starting property of high voltage squirrel-cage alternating current asynchronously motor. It can induce the impact which is brought to motor starting current on power system, and improve the start smoothness with equipment by voltage-reduced starting by way of liquid resistance. It can protect the motor avoid harm by over-load, phase failure, short circuit etc. It is the prefect starting production instead of auto-induction voltage-reduced starter.