介绍了离子液体的定义，发展历史，性质等，重点阐述用于金属离子萃取的离子液体的性质、合成方 法和发展方向。

Ionic liquids, as green solvents, can preferably solve environmental pollution which is caused by using volatile organic solvents. They have become a hot research field in separation of metal ions by solvent extraction. It is introduced in this paper of the definition of ionic liquid, developing history, character, etc. The characteristics,  synthetic methods and development direction of ionic liquids being used for extracting metal ions are emphatically summarized.