Polymerization of butene-1 (B-1) was carried out with a PP-TiCl3/Et(2)AICl/methyl methacrylate (MMA) catalyst system in n-heptane. The influence of temperature, pressure, time and H-2 on molecular weight, isotacticity, and catalytic activity were studied by viscometry, solubility in boiling diethyl ether, and measuring the polymer produced, respectively. The structural properties of the isotactic polybutene-1 (IPB-1) were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and melt flow index (MFI). The molecular weight of the products can be controlled by H-2. It was found that the catalyst showed high isotacticity and activity.