The behavior of oxygen in liquid potassium at the temperature of 550 K was studied by slow neutron scattering. The energy of incident neutrons and elastic peak resolution were 7.5 and 0.35 meV, respectively, in the wave-vector transfer region from 0.4 to 1.3 Angstrom(-1). The quasielastic component of scattering is analyzed and diffusion of oxygen in potassium is discussed.