Objectives : As the attempts to make good uses of laser acupuncture in korean medicine have been steadily carried on, to ensure the safety is needed to increase the use of laser acupuncture. The aim of this study was to examine the safety of using laser acupuncture therapy irradiated with 830 nm laser and 905 nm laser. Methods : Fifteen rats were randomly divided into three experimental groups - Intact ; no therapy group. LAT830 ; laser acupuncture therapy(830 nm) group at GB34 GB39. LAT905 ; laser acupuncture therapy(905 nm) group at GB34 GB39. During eight weeks of treatment, LAT830, LAT905 were treated 2 times weekly, frequency 20 Hz, intensity 20 mW. Test items were mortality, body weight, food consumptions, hematological values, blood chemical values, urinalysis values, absolute organ weights and relative organ weights. Results : Statistically significant differences were not found among 3 groups. The values measured in LAT830, LAT905 and Intact(no therapy) group have shown similar results and it indicated that LAT830, LAT905 had no abnormal influence on the reaction of living bodies. There was little difference on the liver weight of relative organ weight test between laser-treated groups(LAT830, LAT905) and Intact group. Conclusions : In conclusion, laser acupuncture therapies irradiated with 830 nm laser and 905 nm laser caused no abnormal reaction of living bodies. More studies are needed to further establish the safety of many other laser acupuncture therapies.