A strong interaction between double stranded calf-thymus DNA (ds-DNA) and epinephrine but no interaction between single stranded calf-thymus DNA (ss-DNA) and epinephrine were observed by the use of UV-spectroscopy and cyclic voltammetry. It is suggested that the interaction leads to an intercalation of EP molecules into the groove of ds-DNA and the formation of ds-DNA(EP)n complex. A strong interaction between double stranded calf-thymus DNA (ds-DNA) and epinephrine but no interaction between single stranded calf-thymus DNA (ss-DNA) and epinephrine were observed by the use of UV-spectroscopy and cyclic voltammetry. It is suggested that the interaction leads to an intercalation of EP molecules into the groove of ds-DNA and the formation of ds-DNA (EP) n complex.