Formerly called Lilong, which is from the Amis word meaning "red worms" and rendered in Hokkien as A-lí-lóng (阿里壟).

Annual rainfall is 2,000 mm with an average temperature of 23.7 degrees Celsius.

Covering an area of 58.735 km2, Guanshan has a population of 8,160 people (as of February 2023).

Guanshan Township consists of 7 villages, namely Chungfu, Fengchuan, Hsinfu, Lilong, Tekao, Tienkuan and Yuemei, and 135 neighborhoods.

Rice is the most important crop in the township due to its relatively flat terrain suitable for paddy field.