We experimentally investigated the thickness-dependent magnetoresistance properties of InSb films in the temperature range of 12～300 K. The samples were grown on semi-insulating GaAs (100) substrates by molecular beam epitaxy (MBE). It was observed that the thick InSb only can show the semi-classical B2 dependence magnetoresistance resulted from the Lorentz deflection of carriers. At the same time, we found that weak antilocalization (WAL) effect can be much enhanced by reducing the sample’s thickness(with the thickness ～0.1 μm). The thin sample’s WAL magnetoresistance plot can be well fitted by Hikan-Larkin-Nagaoka (HLN) model, which demonstrates that the obseved WAL effect for thin InSb is with a 2-dimension character, which can be associated with the surface/interface states of InSb.