Abstract: In order to discuss the possibility of manufacturing controllable nanostrucures by femtosecond laser, orientation-controllable nanogratings are firstly induced on bulk Ag target by femtosecond pulsed laser whose linear plolarization angle is adjusted continuously by two inserted half-wave plates. Then, based on energy accumulation effects and the dependence of the orientation of self-organized nanogratings on laser polarization angle obtained from our experiments, it is discussed how to controlably induce two-dimensional periodic nanostructrues on target surfaces by femtosecond laser. In addition, conbining the laser scannning approach with muli-beam alternative ablations method, large-area and high-uniformity nanostructures with tunable nanounits are expected to be manufactured. Our inverstigaitons are expected to open a new approach of inducing two-dimensional periodic nanostructures with tunable nanounits and to offer some important clues for controllably manufacturing periodic nanostructures on target surfaces by ultrashort pulsed laser.