Diffusivity of oxygen in liquid bismuth was measured by potentiostatic method and is given bylg(DOBi/cm2·s-1)(±0.042)=-3.706-1377/(TK-1)(804<T/K<1090).Activityof oxygen in bismuth was determined by coulometric titrations and using the measured data standard free energy of dissolution of oxygen in liquid bismuth was derived for the reaction:1/2O2(g)=[O]Bi(at.%)and is given byΔGO(Bi)∘/(J·g-atomO-1)(±720)=-108784+20.356TK-1(753<T/K<1020).Using the above data and Gibbs free energy of formation of Bi 2 O 3 (s), solubility of oxygen in liquid bismuth was derived as a function of temperature and is given by the following expressions:lg(S/at%O)(±0.05)=-4476/TK-1+4.05(753<T/K<988);lg(S/at.%O)(±0.04)=-3786/TK-1+3.36(988<T/K<1020).The present data on solubility of oxygen in liquid bismuth is compared with the literature data.