Abstract: The Plant cuticle is a key barrier to prevent water loss and contaminants contacting and harming plant. In order to understand the leaf cuticle water permeability of green plants under the urban environment with complex air pollution, the water permeability of Ligustrum (Ligustrum lucidum Ait.) leaves that is the common green paper plant in Xi’an was researched. The astomatous cuticular membranes was isolated by 1:1 oxalic acid / ammonium oxalate solution, the water permeability was measured by micro- transpiration chamber, and the thermodynamic activation energy was calculated. The astomatous cuticular membrane water permeability of Ligustrum are 8.03 × 10-8 and 6.66 × 10-7 m s-1 respectively, for 25 ℃ and 35 ℃ condition, and the thermodynamic activation energy of water penetrate is 160.5 kJ mol-1. The reason of water permeability with temperature increasing may be due to temperature effects on the crystal structure of waxy cuticle surface and its continuity.