The biological effects of 36.04 GHz and 50.05 GHz millimeter wave radiation at low power density (1 mW/cm2) on BALB/c liver were studied. The abdominal local surface of the mice was exposed to millimeter waves for 30 minutes daily for 6 days. The results indicate that the millimeter waves have indirect effects on the liver cells. The ultrastructural examination discovered reversible injuries. G-6-Pase was increased after radiation at the 3rd and 5th days. No change was found in DNA content of the liver cells. Meanwhile, it was also found that mitochondria and G-6-Pase were relatively sensitive to 36.04 GHz millimeter wave and endoplastic reticula were relatively sensitive to 50.05 GHz millimeter wave. The changes were found to have dynamic processes 7 days after radiation. From these results and the literature, it is concluded that the indirect specific biological effects of millimeter waves at low power densities are caused by neuronic and humoral systems.