Three kinds of organohalides, including alicyclic halocarbons, aromatic halocarbons and aliphatic halocarbons, were studied as promoters for titanium-based Ziegler-Natta catalysts. The results showed that these three kinds of organohalides all have high activity promotion for titanium-based Ziegler-Natta catalyst. Chloro-cyclohexane (C6H11Cl). chlorobenzene (C6H5Cl), Cl-(CH2)(5)-Cl, CF2ClCFCl2 have very high promotion effect; with these as promoters the activity could be increased by over two times. The promoters could be added into the autoclave individually, or first blended with AlEt3 solution, then added together into the autoclave.