Thermal oxidative aging of carbon black filled SBR was investigated by NMR spectroscopy and imaging. Areas of aged material were localized by parameter-selective H-1-NMR imaging. The image contrast obtained by NMR relaxation parameters correlates with mechanical relaxation spectra of aged and unaged materials. The time dependence of the aging process was monitored by filtered NMR projections for samples with and without aging protectant. The action of the aging protectant can be understood on a molecular level in terms of local inhibition of the aging process for a fraction of chain segments as opposed to a slow down of the characteristic aging time. Furthermore the change in crosslink density as a function of space was derived for an aged sample from the H-1-spin echo decay. The NMR crosslink density shows a linear correlation with the torques measured in a vulcameter for a series of differently crosslinked, unfilled SBR samples.