The elastic α-12 C scattering for l = 0, 1, 2, 3 channels at low energies is studied, including the energies of excited bound states of 16 O, in effective field theory. We introduce a new renormalization method due to the large suppression factor produced by the Coulomb interaction when fitting the effective range parameters to the phase sift data. After fitting the parameters, we calculate asymptotic normalization constants of the 0 + 2 , 1 − 1 , 2 + 1 , 3 − 1 states of 16 O. We also discuss the uncertainties of the present study when the amplitudes are interpolated to the stellar energy region of the 12 C(α,γ) 16 O reaction.