•Corrosion behaviors on different planes of Sc- and Zr- modified Al-Mg alloy processed by selective laser melting were systematically studied using electrochemical measurements.•Microstructures including precipitations, grain size distributions and crystallographic orientations on different planes of Al-Mg-Sc-Zr alloy processed by SLM were characterized using BSE and EBSD.•Inner mechanisms for the anisotropic corrosion behavior were further proposed based on the microstructure analyses. Electrochemical measurements and microstructural analyses were conducted to investigate the corrosion behaviors on different planes of Sc and Zr modified Al-Mg alloy produced by selective laser melting (SLM). Results indicated that the XY-plane exhibited a superior corrosion resistance with a lower current density (icorr =57.1 μA cm-2) compared to the XZ-plane in 3.5 wt.% NaCl solution at room temperature. The microstructural analyses suggested that the anisotropic corrosion resistances of the SLM produced Al-Mg-Sc-Zr alloy related to the quite different microstructures on different planes, which included the molten pool boundary density, Al3(Sc,Zr) precipitation distribution, grain size distribution, and crystallographic orientation.