An integrating sphere is used to measure spectral distribution, calculate total luminous flux and calculate chromaticity coordinates of LEDs. It usually has to consider self-absorption when light source is radiating in the integrating sphere. The LED with coloured parts, such as printed circuit board, heat sink and so on, should be careful in particular. In case of the large enough sphere, self-absorption spectrum of LED has almost flat spectral distribution and its absorption level is few. Hence, the calculated total luminous flux and chromaticity coordinates of LED are almost same, even if self-absorption correction is applied or not. In the small sphere case, self-absorption of LED has spectral distribution with coloured piece and is given some influence. The correction spectrum can be measured individually in each color peace with an auxiliary lamp set up in the integrating sphere. After having spectral correction, total luminous flux comes close to large sphere case and chromaticity coordinates accord with large sphere case.