In order to combine the advantages of porous structure and nanodiamond, a simple and effective route for the fabrication of porous crystalline diamond films on Si substrate was investigated in detail. Methyl formate was used as carbon source to grow the diamond crystalline films during the process of microwave plasma enhanced chemical vapor deposition. H-2 and Ar gas were used as high energy plasma to open the chemical bonds in methyl formate and take methyl formate into the reaction zone respectively. After growth, porous structure thin films were also created by selective oxidation annealing in the air. Then the products were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray photoelectron spectroscopy and Raman spectra measurements. Furthermore, the growth mechanism and enhanced hydrophilic property of porous diamond films were also investigated. (C) 2015 Elsevier B.V. All rights reserved.