Abstractα‐Olefin monomers with different lengths from C4 to C10 were polymerized via a conventional Ziegler–Natta catalyst. It was found that activity of the catalyst decreases with increase in the monomer length as well as introduction of external donor. GPC results exhibited a steady decrease in molecular weight from poly1‐butene to poly1‐decene; however, PDI did not show a clear trend. Based on differential scanning calorimetry and X‐ray diffraction analyses, poly1‐butene and poly1‐decene represented crystalline structure with one and two melting points, respectively, while poly1‐hexene and poly1‐octene showed amorphous nature. The content of isotactic pentads increased from poly1‐butene to poly1‐octene, with maximum value of mmmm = 76%, but decreased again in poly1‐decene. Calculated ΔEre‐si values showed a peak by increasing monomer length which was in line with the experimental results for isotactic content.