The stylar development of Catalpa two species-C. bungeii and C. fargesiihas been investigated with light and electron microscope. The style is characterised by an intermediate hollow/solid type.The epidermal cell of the style has a thick external wall and is covered by an obvious cuticle. The stylar cortex is composed of 6?0 layers of parenchyma cells which contain RER, ribosomcs, paramural body, primary and secondary vacuoles, amyloplastids and so on.In the formation, transfer tissue cells develop all kinds transfer wall-membrane apparatus and has all kinds characterised of transfer梒ell, of secretory type, such as abundant RER, ribosomes, active vascular system, many paramural bodys and secretory substance of vesicular and small tube at the space between wall ingrowths and plasmale-mma.The development of transmitting tissue is divided into three phases: I. Prior to anthesrs, the ingrowths of transmitting tissue cell begins to develop. The RER, ribosome and so on are abundant. II. The florescence, the intercellular spaces is bigger than before and filled with stroma of middle electron dense and all kinds floceulent substances. There are abundant RER, ribosome and paramural in the cell and numerous lomasomes near the plasma membrane in the stroma. III. During the time of pollination, the intercellular spaces of the two species are bigger than before and filled with stroma. The cell disintegrate whilesecretorying. We have comparated the differences between the two species-C. fargesii and C. bungeii in the stylar developing and mechanizm and exp , lained the phenomenon, flowering and without fructification in the C. bungeii.