A method by combination of a colorimeter and a color CCD to measure the brightness and chroma of color pixels of a Light Emitting Diode(LED) was proposed. Firstly, the color pixels of the LED were processed by the CCD camera and the brightness and chroma values of the LED pixels in RGB color space were calculated by image processing. Then, the multi-channel and adaptive matrix between RGB color space and CIE1931XYZ color space were established and the measured data of a few LED pixels were obtained by the colorimeter. With the RGB values and the measured data, the adaptive matrix could be calculated. Finally, the tristimulus values of the LEDs were calculated with the adaptive matrix. Experimental results indicate that the color difference between calculated data and measured data is less than 1 in an appropriate size of adaptive matrix, which can obtain the brightness and chroma of color pixels of the LED rapidly and precisely, and can correct the brightness and chroma of the LED screen. The method can be used to measure hundreds of thousands of LEDs accurately in a short time.