This paper showed the biological response of skin cells, and human newborn foreskin fibroblasts under the irradiation of a photonics-based 300 GHz terahertz source with a beam power of 20 ㎼ which has been usually used as terahertz source of non-destructive testing. We investigated the viability of the cells, cancer-induced biological signals, and aging under the irradiation of terahertz waves.