A modified near-field optical microscope (NSOM) was used to locate reactive sites on polycrystalline titanium immersed in sulfuric acid. Photoelectrochemical imaging was carried out on the NSOM by using a new shear-force feedback method, PEM with simultaneous independent topography (using the tuning fork method) resolved submicron features at reactive sites at inclusions and grain boundaries; Both PEM and topographic images were obtained in-situ with high lateral resolution by using specially fabricated tips with 100 nm aperture.