Abstract: To investigate the pollination characteristics of Primula sieboldii E. Morren，we observed the flowering phenology，flower morphology，the kinds of insects visited Primula sieboldii，the behavior of insects visited Primula sieboldii，the frequency of insects visited Primula sieboldii，and examined the pollen viability，the stigma acceptability，P/O（pollen /ovule rate）and the breeding system of Primula sieboldii，which was introduced to the forest botanical garden of the Heilongjiang Province. The results showed：Primula sieboldii is typically distylous and had two floral morphs within a population：long-styled （Pin）and short-styled（Thrum）morph；The flowering of P. sieboldii take place in May；The pollen viability and the stigma acceptability were both stronger within three days after blossoming；According to Dafni （1992），if the outcrossing indexes were three or four，the breeding system of Primula sieboldii was outcrossing，partially self-compatible，and demanded for pollinators. But by Cruden（1977），if the pollen-ovule ratio（P/O）of Primula sieboldii was from 244 to 361，the breeding system of Primula sieboldii was facultative xenogamy. The pollinators for this species include Papilio maackii M.，Pieris melete M.，Loxostege sticticalis L.，Haemorrhagia sp.，Papilio machaon L. of the Lepidoptera and Eristalis arbustorum L. of the Diptera. In the sunny days，the peak visiting frequencies of vistors is from 10：00 to 15：00 and when it was rainy or the temperature sharply declined，the frequency of visitors was lower obviously.

Key words: Primula sieboldii, pollination biology, breeding system