Sikou Township is separated by Sandie River from Dalin Township in the east and it faces Dapi Township, Yunlin County across Huasing River. These two rivers merge each other about one kilometer away from Sikou and run into Beigang River, forming the mouth of two rivers. As early as more than 200 years ago, the ancestors of Sikou people moved from Fuchien and Guangdong to Taiwan and settled down here, and named the place “Shuangsikou”. In 1895, the Japanese colonists called it “Shuangsikou District”. In the reform of local administrative system in October 1920, districts were replaced by villages; therefore, “Shuangsikou District” was renamed “Sikou Village”. When Taiwan was recovered in August 1945, Sikou Village was transformed into Sikou Township. It is because of the natural terrain of the two rivers that the township is named Sikou. In the early Japanese colonial period, the administrative region of this township was subordinated to Damao Precinct, Chiayi County. When the local administrative system was reformed in October 1920, Sikou District was made Sikou Village, subordinated to Chiayi County, Tainan Eparchy. Meanwhile, the Sijhuang Tribe governed by Sikou District was made subordinated to Singang Village, and the Chailinjiao Tribe governed by Singang Village and the Youcuo Tribe governed by Dapi Village were made subordinated to Sikou Village. So the village totally governed ten tribes, divided into twenty Baos. In August 1945 when Taiwan was recovered, Sikou Village was renamed Sikou Township and the twenty Baos were made fourteen villages. Since then the township has been subordinated to Chiayi County till now.
The ancient residents in Sikou Township were immigrants from Fuchien and Guangdong. The Guangdong dialect spoken by a small part of the immigrants has been assimilated by Fuchien dialect, but there are still some differences in the languages, customs and habits of the immigrants from different provinces. As to religion, except for a few people believe in Catholicism and Christianism, all the other people believe in their original religions as their ancestors did. The customs of their dressing, food, residence, wedding, funeral, and celebrations do not differ from the traditions of our country though Taiwan has been captured by Japan for over fifty years.