Siyang County is a county of Jiangsu, China. It is under the administration of Suqian city.
Siyang is famous for its poplar tree. It is the earliest Chinese county and the Italian poplar tree were the highest poplar coverage of China as China polar tree industry county of the most developed county forestry of China and to learn the unique honor of "China YiYang township of" title of county the name. In addition, SiYang because has the Chinese unique poplar museum, and hold China unique YangShuJie which is famous and well-known.