An electron-donating group (EDG) is a substituent that releases electron density to an adjacent atom, for example an alkyl group acting through the inductive effect. It matters because, by supplying electron density, it stabilises a neighbouring positive charge such as that of a carbenium ion, and so promotes reactions that pass through cationic intermediates. It is the opposite of an electron-withdrawing group, which pulls electron density away.

给电子基团(EDG)是向相邻原子提供电子云的取代基,例如通过诱导效应起作用的烷基。它之所以重要,是因为它通过提供电子云稳定相邻的正电荷(如碳正离子的正电荷),从而促进经由阳离子中间体进行的反应。它与吸电子基团相反,后者把电子云吸引走。