Abstract: Nanosized Fe particles were prepared by flow-levitation method (FLM), and synthesis condition’s effect on Fe nanopowder were investigated based on transmission electron micro-scope (TEM). The results show that FLM can be used to prepare nanosized Fe particles with different diameters, and the particle size of nanosized Fe gradually decreases by reduce the temperature of metal fused drop or increase gases speed. Moreover, increasing the inert gases pressure will decrease the average particle size at 1 500 ℃. However, the change rules of gas pressure’s influence on average diameters of Fe particles will be inexistent at 1 600 ℃.