Abstract . In this paper, we study the next-to-next-to-leading-order (NNLO) QCD corrections for the process e+e? → J/ψ + J/ψ at the B factories. By including the NNLO corrections, the cross section turns negative due to the poor convergence of perturbative expansion. Consequently, to obtain a reasonable estimation for the cross section, the square of the amplitude up to NNLO is used. In addition, the contributions from the bottom quark and the light-by-light part, which are usually neglec...