A microwave plasma system was adopted for the treatment of liquid crystal on LCD panels. The elemental analysis and contact angle observation were performed to evaluate the modification of liquid crystal by plasma treatment. And different atmosphere and treatment time were varied during plasma operation to discuss their influences on the cleaning of liquid crystal on LCD panels. The experimental results indicated that microwave plasma is effective for the modification of characteristics of liquid crystal. The weight ratio of major element in liquid crystal was varied after plasma treatment. In addition, the change in contact angle between the surface of liquid crystal and water also revealed that the plasma process could improve the hydrophilicity of liquid crystal surface and make the water cleaning of liquid crystal on LCD panels to be possible. In this study, oxygen plasma demonstrated a good performance in surface modification of liquid crystal. And the LCD panel treated by oxygen plasma, a 40% cleaning efficiency of liquid crystal could be obtained by direct water cleaning of LCD panel. The plasma treatment is therefore concluded to be a feasible process for the cleaning and recycling of waste LCD panels.