By using rigid microtubules (MTs) prepared by polymerization with guanylyl-(alpha, beta)-methylene-diphosphonate GMPCPP, giant straight-shaped MT bundles were selectively obtained through a dynamic self-assembly process. We demonstrate the effect of the rigidity on the shape and motility of MT bundle composed of GMPCPP-polymerized MTs (GMPCPP-MTs) compared with control MTs that were polymerized with GTP and stabilized with paclitaxel.