A novel kind of electrocatalytic oxygen evolution catalyst was fabricated by introducing g-C₃N₄ ultrathin films onto the surface of attapulgite (ATP) via a simple in-situ depositing technique, combined with freeze-drying and programmed roasting process. The obtained product was identified as ATP/g-C₃N₄. In order to achieve the best catalyst, a series of ATP/g-C₃N₄ composites with different mass fraction of ATP were obtained and marked as ATP/g-C₃N₄-w, where w represents the mass fraction of ATP (w =mATP: (mATP + mg-C₃N₄)= 0.33, 0.40, 0.50, 0.67). Results show that g-C₃N₄ thin layers are uniformly loaded onto the ATP surface via the chemical bond (Si-O-C), which is beneficial to tailor the surface electronic structure of g-C₃N₄ and provide more active sites. Their electrocatalytic oxygen evolution properties in 0.1 mol/L KOH were investigated. It is found that ATP/g-C₃N₄-0.50 presents the best oxygen evolution catalytic performance and has excellent oxygen evolution stability. Its oxygen evolution over potential is 410 mV and the Tafel slope is 118 mV/dec at a current density of 10 mA/cm ². The results suggest that ATP/ g-C₃N₄-0.50 can be used as a potential oxygen evolution catalyst.