The purpose of this study was to evaluate the effects of mental stress measured with heart rate variability(HRV) in healthy adults and to evaluate the effects of laserneedle acupuncture therapy in healthy adults. Methods : 25 healthy volunteers participated in this study. The volunteers were divided randomly, the real laserneedle acupuncture therapy group or the sham laserneedle acupuncture therapy group. First, After 5 minute rest, mental stress was given with stroop color word task and calculation task. And then laserneedle acupuncture therapy or sham laserneedle therapy was done on HT8(少府) for 15 minute. HRV was recorded in 3 period-before stress, after stress, and after laserneedle or sham acupuncture therapy. Results : LF was significantly increased after mental stress. And there was no significant difference between the real laserneedle acupuncture therapy group and the sham laserneedle acupuncture therapy group. Conclusions : This results show that mental stress-stroop color word test and calculation test for 10 minute- contribute to activation of the sympathetic nervous system.