Dynamic study of the growth of TiSi2 nanorods on Si bicrystal was conducted in an ultrahigh vacuum transmission electron microscope. The growth of the nanorods was affected by the underlying dislocation grids significantly. The dislocation grids confined the shape of the nanoclusters and nanorods. Compared to the time of the nanorod remaining at the same length, the elongating time is relatively short. The dislocation network confined the nanorod to match the dislocation interspacing and the step-wise growth of the nanorod was found. The growth mechanism is attributed to the compliant effect. The observation was constructive to the basic understanding of the stress effect on the initial stage of the reaction of metals on Si.