In the current situation in all areas of lighting, color rendering has been more and more attention.Especially the indoor environment, it has high demand for the color rendering.Such as low pressure sodium lamp is close to 200lm / W in luminous efficiency, but monochromatic yellow light only was used for road lighting and very few other occasions.As the United States Department of Energy (DOE) used for indoor lighting LED lights color index from the original 70 (Aug.2007) up to the recent provision of ≥ 80 (Dec.2009).

     Choice in light quality, high luminous efficiency and high color rendering are the key for LED.Shanghai Lighting Association chairman think  that white color is the high photosynthetic efficiency and high color rendering index and meeting the lighting environment or lighting operation , that is the best white color.Endless disputes that  traditional light source and LED replacement market competition and decisive Force issues, director also has its own unique perspective. He think, at present station, LED，LED high light efficiency means that the emission efficiency is higher than the traditional light source.Because the traditional light sources in different occasions as the leading role, if we want to compare with them, we can put the High luminous efficiency traditional light source put in shield as a benchmark, then put the led in the shiled to compare, that is the good way. DOE current document, Some had made the detail decision, there are so much demand for the indoor lighting, Such as home environment, color-rendering index is more than 80 ,it have become popular at present.

     LED coming into lighting industry trends to clear，the goods of high luminous efficiency and good color rendering has showed at the indoor lighting industry to show a fairly good performance and strong development。Therefore, when looking LED light effect, it must be concerned about the color rendering index; Just talking luminous efficiency, color rendering index isn't any significance.