This paper systematically studied pollination ecological characteristics of Xanthium italicum Moretti, an invasive plant in Xinjiang, China, with respect to flowering phenology, pollen vitality, stigma receptivity, pollinators, pollen dispersal distance, maternal and paternal function, and mating system, aiming at providing scientific proof of the mechanism of the successful invasion of the species. The results showed that the flowering period of this alien plant is long-40 days for female flowers and 30 days for male flowers. Its maternal and paternal functions are strong. The number of male inflorescence and that of pollen were as high as 3847 and 37903037 per plant, respectively, while the numbers of female inflorescence and ovules were as high as 3847 and 7694 per plant, respectively. The average seed setting rate was 80.59%, which means that 6200 mature fruits per plant could be borne. The variation pattern of daily pollen vitality showed a single-peak curve:in the morning and evening, the pollen vitality was the lowest, and the activity was up to 99% at 14:00. Pistil stigma had 7-day receptivity once out of involucre, and 3-4 days after flowering, stigma receptivity was at its strongest level. Xanthium italicum Moretti was a wind-pollinated plant. Under the breeze condition of wind speed as low as 4.5km/h, its pollen spread distance could reach as far as 45m, and a large number of pollen distributed in the range of 0-20m from pollen source, which is an efficient pollination strategy for this highly continuously distributed species. This exotic plant has a flexible mating system and the natural seed setting rate at the full bloom stage reached 100%. The results of the bagging test showed that it was self-compatible, and the seed setting rate of natural self pollination was as high as 93%. The seed setting rate of different strains by artificial pollination was also as high as 83%. Therefore, long flowering period, massive male and female inflorescence and pollen grains, high pollen vitality, long stage of stigma receptivity, far anemophilous pollen spread distance, flexible mating system, and high seed setting rate were important factors for the successful reproduction of X. italicum Moretti and the main reasons for its successful invasion.