RESUMEN
<p><b>OBJECTIVE</b>To determine the self-compatibility of Platycodon grandiflorum and the location of microspore germination on stigma.</p><p><b>METHOD</b>The microspore germination of self-pollination, self-plant-pollination and cross-pollination and the pollination microspore germination in and outside of stigma were observed with fluorescence microscopy.</p><p><b>RESULT</b>Most pollens of self-pollination, self-plant-pollination and cross-pollination can germinate on the stigma, and after 24 hours, pollen tube entered into the ovary successfully. Pollinated on the outer-surface of stigma, microspores could not germinate, but on the inner-surface of the stigma when it dehisced most microspores can germinate.</p><p><b>CONCLUSION</b>The compatibility of self-plant-pollination of Platycodon grandiflorum is high. The microspore germination loci is on the inner-surface of the dehisced stigma.</p>