Abstract: The protogonocytes of Ammopitanghus mongolicus(Maxim) Cheng F have drought-resisting characters:low water potential and transpiration,but hight binding water content.The plant has xerophytic struture for restraining transpiration:thick cuticula,concetrated down,depressed stoma,wholly palisade tissue of leaf fresh;it has also developed roots,thus strengthened water-absorbing force.Therefore,A.mongolicus adjusts the water balance in her body depend on absorbing as much water as she can and decreasing water loss from traspiration for adapting arid environment.

Key words: Ammopitanthus mongolicus(Maxim) Cheng F, drought resisting mechanism