Abstract: 6 genera, about 37 species and varieties within Mimosaceae from China were mainly examined with electron microscope. A comparison was made among these genera, putting an em-phasis on the size and the aperture and the ornamentation of the exine, the results are as follows:Their pollen grains unite in 16-celled(except Aberama utile, which is 8-celled). In Acacia, the size of pollen is about 25-30 um, which is the smallest in all genera. And the others are over 50 urn. The apertures and the ornamentations of the exines in Albizia are smooth or subsmooth. It is quite different from Cylindrokelupha, Zygia and Calliandra, which are tuberculate. The genus Aberama is verrucate or subwart. Besides these, the taxomomic significance among them had been discussed.

Key words: China