Growth and quality of lettuce(Lactuca sativa L.)were studied under 3 red and blue LED light intensity,such as 100 μmol·m-2·s-1(RB100),200 μmol·m-2·s-1(RB200)and 300 μmol·m-2·s-1(RB300).Morphological appearances of seedlings were significantly different between light treatments.Compared with the other 2 treatments,plant height,leaf area,root length and specific leaf area of RB100 treatment were significantly greater,and the contents of soluble protein were richer.However,content of VC under RB300 treatment was the highest,and contents of nitrate acid and chlorophyll were the lowest.These results suggest that RB300 treatment is good for improving lettuce quality,while RB100 treatment is good for promoting lettuce growth.