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Regulating the selectivity toward a target hydrocarbon product is still the focus of CO₂electroreduction. Here, we discover that the original surface Cu species in Cu gas‐diffusion electrodes plays a more important role than the surface roughness, local pH, and facet in governing the selectivity toward C₁or C₂hydrocarbons. The selectivity toward C₂H₄progressively increases, while CH₄decreases steadily upon lowering the Cu oxidation species fraction. At a relatively low electrodeposition voltage of 1.5 V, the Cu gas‐diffusion electrode with the highest Cu^δ+/Cu⁰ratio favors the pathways of hydrogenation to form CH₄with maximum Faradaic efficiency of 65.4% and partial current density of 228 mA cm⁻²at −0.83 V vs RHE. At 2.0 V, the Cu gas‐diffusion electrode with the lowest Cu^δ+/Cu⁰ratio prefers C–C coupling to form C₂₊products with Faradaic efficiency topping 80.1% at −0.75 V vs RHE, where the Faradaic efficiency of C₂H₄accounts for 46.4% and the partial current density of C₂H₄achieves 279 mA cm⁻². This work demonstrates that the selectivity from CH₄to C₂H₄is switchable by tuning surface Cu species composition of Cu gas‐diffusion electrodes.