Abstract: We used fluorescence observation to examine pollen germination and growth following reciprocal crosses between Brassica juncea and B. pekinesis. When B. juncea was used as the seed parent, the pollen grains on the stigma could sprout as usual, and most of the pollen tubes could reach the ovule through the style and finish fertilization. With fertilization type, porogamy, chalazogamy and misogamy included, only a few pollen tubes grew poorly and gave rise to the end being swollen and twisted as well as branched pollen tubes. With B. pekinesis used as a seed parent, the growth of the pollen tube was restrained, so only a little tube could go into the ovule and fertilize the eggs because of papilla cells with strong callose effects. The development of a hybrid embryo derived from the reciprocal crosses was observed by means of the paraffin-cut section method. B. juncea and B. pekinesis crossed embryos developed early and in general grew to maturity, and the growth of the embryo and endosperm was relatively normal, whereas in the B. pekinesis and B. juncea hybrid embryo, growth stopped at the heart-shaped stage as did growth of the endosperm at the dissoluble nuclear stage, and finally disappeared in the seed. Thus, B. juncea and B. pekinesis and its crosses are incompatible to some degree.