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Sympatric speciation means that new species ignore the absence of geographic isolation. Compared with allopatric speciation, there are more blanks that need to be filled because of rarity. This paper analyzes the researches about angiosperms sympatric speciation in the past ten years, and focuses on the origin factors and reproductive isolation. Judging seems to be more difficult because of the uncertain historic geographic and close relationship between related species. The origin can be divided into ecological factors that mean destructive selection from special niches and gene factors that include hybridization and polyploids. The former drives ancestor into subgroups with different preferences and strengthened by resource competition and co-evolution. The latter creates species faster in places where the allopolyploid has most contribution, the homoploid hybrid and autopolyploid seem to be wide, but insignificant to the speciation. Similarly, reproductive isolation can be divided into the prezygotic and the postzygotic. The former plays a leading role, with more important flowering isolation and pollinator isolation, while the pollen competition, gamete incompatibility and the later that includes hybrid defect such as abortion, infertility and decline are slight and will accelerate the evolution of prezygotic as well as selfing because of high reproductive costs. In short, sympatric speciation requires the cooperation of various factors and the reproductive isolation can conexist with gene flow, which is driven by the niche competition. Especially when the destructive selection is strong enough, sympatric speciation can continue even if the gene flow is frequent. [ABSTRACT FROM AUTHOR]