Fagopyrum dibotrys is one of the widespread distylous plant in Fagopyrum Mill.of Phytolaccaceae,belonging to national protected 2nd plants.The reproductive traits of this species such as floral basic characteristics,phenology of flowering,pollen/ovule ratio,pollen viability,stigma receptivity,out-crossing index,emasculation,and flower-visiting insects were investigated by experimental observation and bagging treatment to study its reproductive ecology.The results showed that:(1)The individuals of F.dibotrys within a population exhibited two floral morphs as long-styled and short-styled morphs.Diameter in short-styled flower (7.25±0.11 mm) is higher than that in long one (6.79±0.11 mm).Stigma and anther heights in long-styled flowers are 3.39±0.04 mm and 1.80±0.02 mm,while in short-styled flowers are 1.89±0.04 mm and 3.19±0.06 mm,respectively and exhibiting reciprocal herkogamy.(2)F.dibotrys flowered during August to October in Dajing,Jinggangshan Mountain.The lifespan of a single capitulum is approximately 15 to 23 days,1 to 3 days for a single flower,the pollens of inner anthers scatter first,followed by the outer’s during flowering.The pollen viability of short-styled flower is higher than that of long one,but each short-styled flower has lower pollen number,which shows the phenomenon of the flower’s self-regulation.(3)Bagged experiments suggest that F.dibotrys is self-incompatible,but compatible for intramorph and intermorph,the P/O rations was 810±40.48 and 526.5±42.24,which suggests that the breeding system was facultative outcrossing.(4)The main floral visitors are insects of Hymenoptera,Diptera,Lepidoptera,Hemiptera and Odonata,12 common species for the two morphs,14 species for long-styled flower,35 species for short-styled flower,which showed that the short-styled flower has stronger attraction to visiting insects than long-styled flower.It could be concluded that F.dibotrys is a typically distylous species with strict self-incompatibility,but a little homomorphic compatibility.