Nanocrystalline Ti powder was prepared using cryogenic mechanical milling. The evolution of morphologies and structures for Ti powder during cryomilling were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The experimental results show that the particle sizes decrease from original 45 mm to 5 mm after 8 h cryomilling. Embrittlement cracking is the dominating way of the refinement for Ti particles. The time required for preparing nanocrystalline Ti powder by cryomilling technique is only 8 h.