Population distribution, habits and characteristics of Aster subulatus were be investigated in this project. Based on these results, appropriate control methods would be carried out for preventing the expansion of Aster subulatus population, and maintain local biodiversity in Miaoli. Results showed that Aster sublatus invaded nearby area are scattering including Yuanli Township, Sanyi Township, Jhuolan Township, Dahu Township, Gongguan Township, Miaoli City, and Tongsiao Township in Miaoli County; Howli Township in Taichung County; and Ermei Township in Hsinchu County. Removing period during bolting, flowering and before seed maturation is recommended.