Self-assembled micronsized flower silver (Ag) particles were synthesized using AgNO3 as starting material by a stainless steel assisted vitamin C (Vc) reduction method. X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to characterize the phases and the morphologies of the products. The results show that the micronsized flower Ag particles with 1~ 6 μm size can be rapidly and routinely produced on relatively large scales, which are composed of nanoplates or nanorods with the thickness of around 200 nm. The growth process of the micronsized flower Ag particles was investigated and their growth mechanism was proposed. It is revealed that the micronsized flower Ag particles might be assembled from small particles step by step. The presence of stainless steel and temperature plays an important role in determining the geometric shape and the size of micronsized flower Ag particles.