Using the Bs meson wave function extracted from non-leptonic Bs decays,we evaluate the rare decays Bs →e+ e-γ (e =e,μ) in the standard model,including contributions from all four kinds of diagrams.We focus on the contribution from the four-quark operators,which were not taken into account properly in previous studies.We find that the contribution is large,leading to the branching of Bs → e+ e-γ being nearly enhanced by a factor 3 and up to 1.6 × 10-8.The predictions for such processes can be tested in the LHC-b and B factories in the near future.