LaCoO3 powders synthesized by Pechini process were pulverized by planetary ball-milling to decreaseparticle size and characterized as a catalyst in alkaline solution for oxygen reduction and evolution reaction (ORR& OER). The changes of physical properties, such as particle size distribution, surface area and electric conductivity,were analyzed as a function of ball-milling time. Also, the variations of the crystal structure and surface morphologyof ball-milled powders were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM),respectively. The electrochemically catalytic activities of the intrinsic LaCoO3 powders decreased with increasingball-milling time, but their electrochemical performance as an electrode improved by the increase of the surfacearea of the powder.