A highly hydrophobic surface with nanoscale roughness was prepared by coating with a short-chained fluoroalkylsilane The freezing behavior of a water droplet on the surface was then investigated Freezing initiated in the vicinity of the three-phase contact line, producing a sharpened onion-like top on the droplet. The result of the freezing ratio at each time and the volume ratio at each height demonstrates the possibility that freezing advanced linearly in a vertical direction