Petrocosmea qinlingensis is a Class-Ⅱ National Key Protected Wild Plant distributed in the Qingling Mountains, which is in an endangered state. The pollination biology and breeding system of P. qinlingensis with wild or artificially cultivated were studied using observations and artificial pollination experiments. The results show that: (1) The flowering period of the P. qinlingensis population is from the beginning of July to the end of September, which coincides with the rainy season in Hanzhong, resulting in pollination failed. The corolla tube is deeper, which is not conducive to insect pollination, The stigma is higher than the anthers, needing pollinator assistance in pollination. (2) The stigma has the receptive before the anthers dehiscence, and the highest level of receptive is from the fourth to sixth day. Pollen viability reaches the peak on the 5th day. Although there is an overlapping period between pollen and stigma, the overlapping period is too short, only 1-2 days. (3) The average frequency of flower visiting insects is low, and the residence time of each flower visiting is short, which seriously affected the flower visiting behavior of insects in rainy weather. (4) The results of breeding system testing and bagging experiment show that pollen-ovule ration (P/O) is about 77.92, and the hybridization index (OCI) is 4. P. qinlingensis is a mixed-crossing system using self-compatibility as the main breeding form and concomitance out-crossing and there was no apomixis. Pollinators play an extremely important role during the pollination process. (5) The seed germination test show that the germination rate of P. qinlingensis is low under natural conditions, only 23.33%. The above results indicate that the pollination of P. qinlingensis is highly dependent on insects, greatly affected by weather, The overlap period of pollen and stigma activity is too short, and the seed germination rate is low under natural conditions, which may be the key reasons for the endangerment of P. qinlingensis.