Abstract:In order to understand the pollination characteristics of Melastoma sanguineum Sims, the florescence, floral character, visiting insects of M. sanguineum grown in three habitats were observed in Bawangling National Nature Reserve, and the indexes related to breeding system were determined. There is no nectar secreted throughout the whole florescence. The petals play the role in attracting insect visitors. Apoidea, Syrphidae, Tutelidae and etc. are the main flower-visiting insects, while carpenter bees and bumble bees are the main pollinators, and carpenter bees are the most effective pollinators. The flowers have heteromorphic stamens, of which the long and short stamens have clear functional differentiation in the pollination process, suggesting that it is the pollination strategy of M. sanguineum. Melastoma sanguineum is a self-compatible out-crossing species. The fruit setting rates are significantly high in both artificially out-crossed and self-pollinated flowers. There is no reproductive security phenomenon, such as apomixis, active self-pollination and lag self-crossed, and pollinators are necessary for M. sanguineum. Its breeding system is typical facultative inbred type. The habitats with low temperature difference between day and night, and high relative humidity, such as in forest and forest gap, are better for prolong blooming period of population, while development of flowers in forest edge with sufficient sunlight and high temperature is fast and stigma receptivity is early. So, the pollen, pollinators and environment condition are main factors effecting pollination of M. sanguineum in the field.