Abstract:To explore the factors that cause the low fruit setting rate of pure line planting of Lycium barbarum NQ-2, the flowering characteristic, pollen viability, stigma receptivity and breeding system of L.barbarum NQ-2 were studied by means of observation on pollen viability, stigma receptivity, pollen-ovule ration, outcrossing index, emasculation, bagging and artificial pollination using Ningqi 1 as control. The results showed that: (1)The florescence of individual last 3-4 days, the pollen viability was high during the 1st-3rd day, then began to decline, the life span of pollen was more than 9 days; (2)The stigma has receptivity one day before flowering, the receptivity was strongest on the 1st day, and on the 3rd day stigma lost its receptivity; (3)The pollen-ovule ratio (p/o) is 8615, out crossing index is 4; Based on the result of emasculation, bagging and artificial pollination studies, the breeding system of NQ-2 should belongs to obligate xenogamy. The self-incompatibility is the main reason for the low fruit setting rate of pure line planting of NQ-2.