Light impacts layer hen's welfare and production. This study investigated the effects of a novel LED light system on blood physiological variables in laying hens. In each of the two trials, 320-layer pullets were allocated to 16 groups of 20 birds. Treatments included the prototype LED lighting (two rooms) and the conventional 2700 K LED bulbs (two rooms). On each sampling day, blood samples were collected and analyzed immediately. Results show that only a few physiological variables were affected by treatments, but age had effects on most examined variables. No effects of treatments or age on plasma corticosterone signify a similar level of physiological stress.