Chemical vapor deposition (CVD) is one of the most popular film deposition methods on solid substrates. We propose a new powder synthesis method utilizing CVD process, that uses a liquid instead of a solid as a substrate. The gas close to the liquid surface and/or dissolved in the liquid was decomposed by laser irradiation and particles were synthesized. Water was used as a liquid, because of its large solubility. Diamond like carbon particles were synthesized by ArF excimer laser irradiation to the methane dissolved in water. Grain size of the particle synthesized from the gas close to the liquid surface was 50-200nm, and that from the gas dissolved in the water was 200-700nm. Grain size could be varied with laser power. Energy dispense spectroscopy (EDS) clarified that the powder mostly consisted of carbon, and oxygen and nitrogen could not detected. High resolution transmission electron microscope (HR-TEM) and electron diffraction revealed that the powder was composed of diamond like carbon (DLC) and multiwall carbon nanotube was grown on the DLC