In this paper a novel classification of chain reactions, in which participate radicals, having properties of electron donors and playing the role of chain carriers by electron transfer is offered. The reactions discussed are distinguished from classical, that means radical, chain reactions, since electron transfer processes play a decisive role in their mechanism. Three groups of chain reactions, including various types of electrondonor radicals, are turned out on the basis of a number of literature examples. In case of SRH1 (AH·)‐reactions AH· radicals, generated from a hydrogen‐atomdonor AH2, act as an electrondonor. More powerful electron‐donors than AH· are A· anion radicals in SRH1(A·)‐reactions. In SRZ1‐reactions arise radical adducts, bearing electron donor properties. In this review are also discussed some proposals for the further development of the studied chain reactions.