Picoplatin is a kind of new cancer drugs,but its mechanism of action in the body is not clear.Using fluorescence spectroscopy technology to study the interaction between picoplatin and bovine serum albumin (BSA) under simulated human physiological conditions(Tris-HCL buffer solution system,pH7.4),picoplatin has a quenching effect on the endogenous fluorescence (336nm) of BSA.Under the condition of room temperature 296K and simulated human temperature of 310K,the fluorescence extinction efficiency of picoplatin to BSA decreases with the increase of temperature,which belongs to static annihilation.The binding constants at 296K and 310K were 4.032×10^4and 2.181×10⁵L·mol－1,respectively,and the number of binding sites were 1.0955and 1.3105,respectively,indicating that picoplatin had only one target for BSA.According to the calculated therm odynamic parameters of ΔH＞0and ΔS＞0,it is shown that the hydrophobic force is mainly between the picoplatin and the BSA molecule,and the combined reaction is a heat-absorbing reaction.The results of time-resolution fluorescence sh ow that the 212^th Trp residue in the BSA may be the target of picoplatin,and the increase of temperature is favorable for the forward reaction of picoplatin with BSA.