Five titanium complexes TiCl3(OAr) (Ar = C6H5, 2,6-Me2C6H3, 2,6-i-Pr2C6H3, 2,6-t-Bu2C6H3, 4-Me-2,6-t-Bu2C6H3) were immobilized, respectively, on MgCl2 in semibatch reaction to form supported catalysts for olefin polymerization. Comparing with the catalysts prepared by immobilizing TiCl3(OAr) onto MgCl2 in batch reaction, the catalysts prepared by semibatch reaction have lower titanium content and higher ArO/Ti ratio. The aryloxy-containing catalysts studied in this work showed higher ethylene/1-hexene copolymerization activity and higher 1-hexene incorporation rate than the blank catalyst when activated by triisobutylaluminum. Similar effects of the aryloxy ligand were observed when the copolymerization is conducted in the presence of hydrogen. Introducing aryloxy ligand in the catalysts either by semibatch or batch reaction caused similar effects of enhancing copolymerization activity and α-olefin incorporation rate. Mechanism of the effects of aryloxy ligand has been discussed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41329.