La0.7Sr0.3MnO3 (LSMO) tunneling magnetoresistance (TMR) junctions have been successfully fabricated on step-edge (001) SrTiO3 substrates with various step-edge conditions. We report the fabrication techniques of LSMO step-edge TMR junctions in which the standard photolithography and ion-beam etching techniques are used to control the step angle and step height. We study the influence of step-edge conditions on the resistance and MR behavior of LSMO TMR junctions. It is found that the magnitude of junction resistance increases with an increase of step angle or with a decrease of d/H ratio, where d is the film thickness and H the step height. Based on our results, we conclude that a suitable d/H ratio of similar to0.5-0.9 with a high step angle of phi greater than or equal to 70degrees can be regarded as the optimum conditions for the fabrication of step-edge TMR junctions. (C) 2003 Elsevier B.V. All rights reserved.