Abstract
The weak-localization correction to the Boltzmann conductivity due to impurity scattering is calculated in metallic carbon nanotubes within the effective-mass approximation. The correction is positive for the impurity with interaction range larger than the lattice constant, while the impurity with shorter interaction length turns the correction into a negative value destroying the anti-localization. The crossover from anti-localization to weak localization is realized by controlling the coherence time.