The population of the township consists mainly of the Paiwan people with a substantial Rukai minority.

'people of Tjimur communinty'[2]) into Hokkien (Chinese: 山豬毛; Pe̍h-ōe-jī: Soaⁿ-ti-mn̂g; lit.

Following the handover of Taiwan from Japan to the Republic of China in 1945, the area became Sandimeng Township (三地盟鄉; Sāndìméng Xiāng) but the name was changed again in 1947 to Sandi Township (Chinese: 三地鄉; pinyin: Sāndì Xiāng; Pe̍h-ōe-jī: Sam-tē-hiong) but the Taiwanese pronunciation of Soaⁿ-tē-mn̂g continued to be commonly used.

During the Japanese era, Sandimen was grouped with modern-day Majia Township and Wutai Township as "Aboriginal Areas" (蕃地), which was governed under Heitō District (屏東郡) of Takao Prefecture.

The township comprises 10 villages: Anpo, Dalai, Dashe, Dewen, Jingshan, Jingye, Koushe, Mani, Saijia and Sande.