Abstract: Commercial carbon cloth (CC) is an ideal electrocatalysis material to produce oxygen evolution reaction (OER) due to its high conductive and 3D flexible structure, but the lacked active sites limit its application. For improving its OER performance, the present study proposed an effective method combining plasma and acid treatment to introduce oxygen-containing functional groups and produce more active sites on its surface. Compared to the pristine CC, the plasma and acid treated carbon cloth (PN-CC) delivers a reduced overpotential by 34.6% to achieve current density of 10 mA cm⁻². The Tafel slope declines from 97.5 mV dec^–1 (pristine CC) to 55.9 mV dec^–1 (PN-CC), showing an increased OER kinetic. Additionally, PN-CC electrocatalyst shows outstanding stability after 5000 cycles or 25 000 s. The combination of plasma and acid treatment shows a significant potential in surface modification for electrocatalysts.