One-dimensional periodic nanocrystalline silicon (nc-Si) arrays were fabricated by laser interference crystallization combined with one-dimensional phase shifting grating mask (PSGM). The laser energy density irradiated on the surface of samples with different thicknesses of a-Si:H can be modulated by the PSGM with periodicity of 400 nm. Raman spectra confirmed the crystallization of the irradiated stripe-patterned area of the samples. The transmission electron microscopic and atomic force microscopic images demonstrate that the periodicity of one-dimensional nc-Si arrays is the same as that of the PSGM. And by controlling the laser energy density, a stripe width of 30 nm in each period was obtained as the thickness of a-Si:H decreased from 10 to 4 nm. The high resolution transmission electron microscope images show the clear crystalline lattice of nc-Si within the stripe patterns.