The flowering process and pollinators of Paeonia ludlowii, an endemic plant in Tibet, which introduced and cultivated in Luanchuan County, Henan province were observed in 2019 and 2020. Pollenovule ratio(P/O), outcrossing index (OCI), pollen viability and stigma receptivity, artificial pollination were used to study flowering characteristic and breeding system type. The result showed that: (1) P. ludlowii flowers bloomed during the day and closed at night, the flowers tilted down as corolla unfolded and tilt upward as corolla closed. (2) Flowers lightly fragrance with intrafloral nectary, the main secreting site was between petal and ovary. (3) The florescence of group was from May 17 to June 19 in 2019, lasting 35 days, which was a concentrated flowering pattern, well a single flower bloomed (8.95±1.28) d. (4) The pollen activity was high from the 2nd day to the 6th day in florescence, the stigma got receptivity 1 day before flowering and lasted for 12 days. (5) The P/O was 119 356.31-731 238.07, OCI was 4, its breeding system type is outcrossing, partial selfinbreeding, and pollinators were required. (6) it may have unstable apomixis, and emasculation will severely affecting seed setting. (7) The main pollinators were Apismellifera ligustica, Ceratina sp., Halictus sp., Eristalis cerealis and Episyphus balteatus. Among them, A. ligustica visited flowers most frequently. (8) The seed setting of side flowers were more stable than that of top flowers, it is recommended to pollinate side flowers on the 3rd and 4th day in florescence to obtain a higher seed setting rate in crossing breeding.