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The theory of disordered metals in which both localization effects and electron-electron interactions are taken into account, appears to explain the negative magnetoresistance of granular aluminum. At high fields, the conductivity increases as √H, with temperature and resistivity dependences well described by the theory developed by Lee and Ramakrishnan to zero and first order in F(kFℓ)−12, where Fis the Hartree screening factor, kFthe Fermi wavevector, and ℓ the mean free path between elastic scatterings. At high resistivities and low fields there are clear disagreements that probably arise from the need to consider higher order terms. This view is supported by the recent scaling theory of Khmel'nitskii and Larkin based on the phase transition analogy to the metal-insulator transition.