Abstract: Oleanolic acid was chemically modified to improve its interaction with bovine serum albumin, thus to increase the mutual binding ability. As a lead compound, oleanolic acid reacted with Jones-reagent, then methyl iodide and finally hydroxylamine to obtain four different derivatives. Their structures were confirmed by IR and ¹H NMR analysis. The interaction between these derivatives and bovine serum albumin and the effect of temperature and trace metal ions as Cu²⁺ and Co²⁺ on the interaction were investigated by fluorescence spectroscopy. All these derivatives exhibited improvement of the interaction compared with oleanolic acid with 16 times stronger for OA₂. The interaction also increased with the presence of trace metal ions as Cu²⁺and Co²⁺. These results indicate that chemical modification can improve the interaction of oleanolic acid with bovine serum albumin.