Abstract: Calligonum ebi-nuricum is a desert shrub and a rare species in Xinjiang. Based on the observation of the sample plants in the field，with the focus on the outcrossing index，pollen-ovule ratio （P/O），pollen vitality and stigma receptivity and artificial pollination experiments，a systematic research on the floral syndrome and breeding systems of C. ebi-nuricum was conducted. Results showed：The flowering stage of populations was approximately 70 days from May to July，and the life span of a single flower was 4–6 days in habitat. The flowering process for one flower of the species can be divided into five periods：Bud stage，prophase of flowering，blooming stage，decadence stage and fade stage. The flowers of C. ebi-nuricum are bisexual and the anther always exceeded stigma during the whole flowering process. Dichogamy and protandrous. Pollen had stronger vigor from first to fourth day of blossoming，and stigma had higher receptivity from second to fifth day of blossoming. The crossing index was 5，pollen-ovule ratio was 2 464. Based on results of artificial pollination experiment，the breeding system is out-cross system，self-compatible partly，and it needs pollinators. Pollinators were mainly bees，ants，fliesand beetles.

Key words: Calligonum ebi-nuricum, floral syndrome, flowering process, breeding system