We investigated pollinia development in rare orchid Vanda coerulea using paraffin sectioning in order to provide some embryological data to clarify the generic delimitation of AeridesVanda alliance. Results are as follows: (1) initially anther primordia were differentiated into a pair of thecae containing two microsporangia. And then, a sterile septum was formed longitudinally and unequally in each microsporangium during microsporogenesis. Finally, the septum was totally absorbed leading to 2 cleftpollinia at ripen anther stage. (2) The development of anther wall was of massive type due to 5-9 layers including a transient epidermis, 2-6 endothecium layers, a middle layer and a uninucleated tapetum. (3) Microspore mother cells underwent a successive cytokeinsis during meiosis resulting in some tetrahedral or isobilateral microspore tetrads. Microspores retained in tetrads and developed into 2celled pollen tetrads. The pollen tetrads arranged compactly within the collapsed anther wall and formed 2 cleftpollinia in anther. These embryological features provided new data to the taxonomy of Vanda S. S.