In order to investigate the effect of the introduction of hydrophobic, hydrophilic, bulky and/or aromatic groups on the set of wool, wool fibers and fabrics were treated with butyl, cyclohexyl phenyl and α-naphthyl isocyanates (NI), glycidol and phenyl glycidyl ether (PGE), and their setting properties were examined. The settabilities were evaluated by three test methods : extension-settability test of single fibers, crease-settability tests of fabrics by the IWS method using Hoffman steam press, and by the handy method using a home steam iron. The introduction of both cyclic and aromatic groups showed a pronounced effect on the settability of wool. The wool treated with PGE as well as that treated with a bulky aromatic compound, NI, were markedly set. Furthermore, discussions were made about the influences of these treatments of wool fabrics and fibers on their mechanical properties, yellowing and shrinkage.