In this work, various types of pure nanoparticles are synthesized by pulsed laser ablation. A novel method using laser ablation is presented to synthesize and separate different sizes of nanoparticles. Laser ablation is applied as a physical and environmental friendly method to generate a variety of nanoparticles in air-based environments. By tuning laser beam horizontal and placing target materials vertically to the substrate, nanoparticles can be generated and separated automatically depending on their sizes. The size distribution is evaluated by optical microscope and nanoparticles are counted according to their diameters. The diameter of the particles ranges from 30nm to 5000nm. This work provides a versatile means to collect many types of uniform functional nanoparticles for a wide range of applications.