Abstract: A rubber particle is enclosed by semi-unit biomembrane．its surface is with negative charge which adsorb water molecular. The amount of rubber particle in a cell are so many that they show significant capability of binding water. The plants which synthesize rubber improve their capability of binding water through increasing synthesis of rubber particle for stress resistance. smaller rubber particle fuse into larger one for decreasing amount of bounding water through decreasing total of surface of rubber particle in a cell when stress relieve .