A plasma lighting system includes a magnetron configured to generate microwaves, and a bulb filled with a main dose and an additive dose. The main dose and the additive dose generate light under the influence of microwaves and have the maximum intensities of respective intrinsic wavelengths at different wavelengths. A waveguide is configured to guide the microwaves generated by the magnetron to the bulb. A motor is configured to rotate the bulb. A sensor is configured to sense the intensity of light having a specific wavelength emitted from the bulb. A controller is connected to the motor. The controller adjusts the Revolutions Per Minute (RPM) of the bulb based on the intensity of light having the specific wavelength sensed by the sensor. With this arrangement, a Color Rendering Index (CRI) of the plasma lighting system may be adjusted during operation.