Nei-men is located in the northeastern region of Kaohsiung County and is one of the townships at the border of Kaohsiung County and Tainan County. Zuo-jhen Township and Long-Ci Township of Tainan County are to its west, Nan-hua Township of Tainan County and Shan-lin Township of Kaohsiung County are to its north, Cishan Township of Kaohsiung County is by its east, and Tian-Liao Township of Kaohsiung County is to its south. Nei-men Township is a low-altitude basin amidst the mountains. It has an area of 95.6624 square kilometers. And it is within an hour drive from Kaohsiung City via Freeway No. 10. towards Cijin.