2-Hydroxyethyl acrylamide was successfully polymerized via single-electron transfer initiation on the silicon surface and propagation through the reversible addition-fragmentation chain transfer (SET-RAFT) polymerization at ambient temperature for different polymerization times. This work is the first time application of the surface-initiated SET-RAFT mechanism to afford the preparation of well-defined poly(2-hydroxyethyl acrylamide) [poly(HEAAm)] brushes at ambient temperature. The polymerization was well controlled and produced poly(HEAAm) brushes on the silicon surface with a well-defined target molecular weight. The controlled nature of the polymerization was further demonstrated in the presence of sulfur atoms at the chain ends in X-ray photoelectron spectroscopy experiments. The grafting density (σ, chains nm −2 ) and the average distance between grafting points (D, nm) were found to be 0.42 chains nm −2 and 1.74 nm, respectively, indicating moderate grafting density.On the other hand, in the preparation of polymer brushes on the solid substrate via surface-initiated controlled/living radical polymerization (LRP) methods, a uniform and dense layer of immobilized initiators is required. The deactivating species in the SET-LRP are very important for the fast construction of a balance between the dormant and the active chains. Mostly, the