▎ 摘　　要

For large areas, fast and simple method for measurement of graphene's carrier density is critical to the application of graphene. The paper presents a method for measurement of graphene's carrier density using infrared phase contrast microscopy. The method is based on the fact that, in far infrared and some middle infrared band, the phase change is more sensitive than the intensity change in graphene when the light passes through it, and the ratio of phase and intensity becomes bigger with the increase of carrier density. The method can be two-dimensional, fast and convenient to detect graphene carrier density. The method will contribute to future research and application of graphene.