The present paper reports photocatalytic degradation of bovine serum albumin (BSA) by TiO2 under near UV (365 nm) irradiation. Ultraviolet-Visible spectrometry, FTIR spectrometry and HPLC were used to study the degradation and characterize the final degradation products. It was found that under near UV irradiation, BSA (0.1 g x L(-1)) can be totally degraded to small fragments by TiQ2 in 5 h. Total mineralization of BSA (93.5%) is reached after reacting for 40 h. C, N and S in BSA are mineralized to give CO2, NO3- and SO4(2-). It is suggested that the degradation of BSA happens in two steps: first to small fragments, then further mineralized to small inorganic molecule. The absence of UV irradiation or TiQ2 can only lead to partial degradation of BSA (30%) in 5 h and no CO2 is observed even in longer reaction time.