Abstract: The aim of the present paper was to find out a simple and easy- to-go method to observe the stomatal movement of a mangrove plant Aegiceras corniculatum . The new method was used to study the following areas, inculing the effect of exogenous nitric oxide (NO) on the leaf stomatal movement under different concentrations and different treated time , the
effect of Ca²⁺ in the regulation of stomatal movement induced by exogenous NO, the interactional effect between NO and H₂O₂ in the regulationb of stomatal movement. The results suggested that the oxhide pastern print was the best way to observe stomatal movement of A. corniculatum compared with the blender method and the nail enamel print method. The stomatal
closure induced by NO was associated with Ca²⁺ in dose dependent manner. It was also proved that a rapid stomatal closure could be co- induced by NO and H2O2 in A. corniculatum guard cells .

Key words: Nitric oxide