Abstract: The processes of megasporogenesis, microsporogenesis and the development of female and male gametophytes of Catalpa speciosa Warder were observed by serial paraffin sections. The results are as follows: the ovule has 2 locules and is anatropous, single-integument, and thin-nucellus. Sporogonium developed megaspore mother cell directly. The development of embryo sac is of polygonum type. There are five stamens in C.speciosa Warder, including three degradation and two fertile stamens. Its anthers have 2 mirosporangiates, and the tapetum belongs to glandular type. The tetrads are tetrahedral. The pollen grains are four celled at shedding.

Key words: Catalpa speciosa Warder, megasporogenesis and microsporogenesis, development of female and male gametophytes