This letter introduces the properties of superhydrophobic metal carboxylate surface. The relationship between wettability of superhydrophobic metal carboxylate and substrate roughness has been studied by choosing sandpaper with roughness range from 80 to 2000 grit as substrates. The superhydrophobic effect has been found interrelated to substrate roughness. This phenomenon has been analyzed both experimentally and theoretically. This work has guidance significance to control the wettability in industrial production.