Abstract: Breeding system is theoretically considered as a principal factor which has the most apparent effects on plant evolution and population genetic structure. In this paper, studies were made of the floral traits, pollen viability, stigma receptivity, pollen-ovule ratio, out-crossing index, fruit sets under a serious pollination treatments, and pollinating observation of Magnolia liliflora. The result showed that:(1) The flowers of M. liliflora were amphoterics. The life span of the flower was about 15 days. (2) The pollen viability of the flower was relatively high in 9 hours after blooming and became low 24 hours later. The pollen hardly had any viability after 56 hours. The stigmatic receptivity of the flower was strong during three days and then began to decline from the 4th day. On 7th day, the stigma completely lost its receptivity. (3) The effective pollination way of M. liliflora was insect pollination. (4) M. liliflora was out-crossing, partly selfcompatible, requiring pollinators.