Nano-particles possess unique characteristics of the optical, electrical and mechanical properties. Many efforts have been made on the fabrication and characterization of nano-particles during the recent decades. In this study the synthesis of metallic nano-particles by condensation method is generated by a pulse laser irradiated on a metallic target with a rapid evaporation in an inert jet flow condenser. In the simulation analysis of local ablation phenomenon in gas plume, which was induced by laser ablation, small particles with narrow distributions were expected in the experiment. This study applies the computational fluid dynamics (CFD) analysis to simulate the condensation process of the metallic particles under laser irradiating, in order to understand the formation mechanism of the nano-particles for broader applications to the mass production. The flow analysis was adopted to investigate the process design from the macroscopic and microscopic views respectively to predict the process characteristics in the laser ablation and condensation for nano-particle formation.