The binding of one fluorine including triazole (C(10)H(9)FN(4)S, FTZ) to bovine serum albumin (BSA) was studied by spectroscopic techniques including fluorescence spectroscopy, UV-Vis absorption, and circular dichroism (CD) spectroscopy under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by FTZ was the result of forming a complex of BSA-FTZ, and the binding constants (K (a)) at three different temperatures (298, 304, and 310 K) were 1.516 × 10(4), 1.627 × 10(4), and 1.711 × 10(4) mol L(-1), respectively, according to the modified Stern-Volmer equation. The thermodynamic parameters ΔH and ΔS were estimated to be 7.752 kJ mol(-1) and 125.217 J mol(-1) K(-1), respectively, indicating that hydrophobic interaction played a major role in stabilizing the BSA-FTZ complex. It was observed that site I was the main binding site for FTZ to BSA from the competitive experiments. The distance r between donor (BSA) and acceptor (FTZ) was calculated to be 7.42 nm based on the Förster theory of non-radioactive energy transfer. Furthermore, the analysis of fluorescence data and CD data revealed that the conformation of BSA changed upon the interaction with FTZ.