At plant factories, researches on plant and light sources have been continuously conducted to produce wanted plants through minimum light source scanning in order to reduce energy. There have been many researches on effects of light quality and luminous intensity on leafy vegetables, but there haven't been so many researches on nutritional contents of those leafy vegetables. As nutritional contents have great effects on the growing process of red leaf lettuce, researches on red leaf lettuce following luminous intensity, light quality and photoperiod should be conducted. In this study, an experiment was executed about the growth using six mixed light sources (the proportion of Red:Blue 9:1, 8:2, 7:3, 6:4, 5:5 and Red:White 7:3), five single-color light (Red 647nm, 622nm, Blue 463nm, 450nm, white) and three photoperiods (Red:Blue 8:2, photoperiods 18h, 15h and 12h) to clarify the influence of LED on growth of lettuce and vitamin C contents. In addition, a comparative experiment was conducted on Feb. 20-March 26 and April 9-May 10, 2012 to know growth and nutritional contents of lettuce depending on temperature changes inside experiment equipment. According to the study, the red light 647nm, a single light source, had the greatest influence on growth of red leaf lettuce, followed by blue light 463 and 450nm, and all white. About growth of roots and stalks liveweight, 7:3 (Red:Blue) and 7:3 (Red:White) influenced much on growth of foots. Regarding growth of lettuce following the photoperiod, roots (liveweight), root length, liveweight and number of leaves became higher, as the photoperiod got longer. The length and width of leaves were higher in the photoperiod of 8:2 (Red:Blue) 12h. Vitamin C contents of lettuce following light treatment was highest in the mixed light 7:3 (Red:White). In the single-light treatment, the figure was highest in blue light (450nm). In comparison of before and after temperature changes in experiment equipment, there was a significant difference as high as about two-three times after a temperature rise, indicating that vitamin C contents of red leaf lettuce became higher with rising temperature. Vitamin C contents were higher in the blue light source.