Radio-frequency (rf) microplasma discharge of argon was successfully generated within an ethanol (EtOH) solution and applied for the synthesis of carbon microstructures. The plasma state depends on the flow rate of argon as well as the EtOH concentration. The argon related species are consumed mostly for dissociating EtOH at concentration of over 10%. The carbon related microstructures such as particle and nanotubes (CNTs) were formed directly on c-Si utilizing a microplasma jet of argon generated within ethanol solution, the average size and number density of carbon related products could be controlled by adjusting the ethanol concentration. The determining factor of average size and number density of carbon microstructures are discussed in terms of the surface reaction within ethanol solution. (c) 2007 Elsevier B.V. All rights reserved.