The county is inhabited by several ethnic minorities, including the Miao, Yi, Gelao, and Zhuang. Ethnic minorities account for a majority of the county's population. The county is considered an impoverished area; in 1993 the county-wide income was only 28.09 million yuan (US$3.6 million), with the net income for farmers on average being only 368 yuan (US$48) per person. The economy centers primarily on agricultural production, including tung oil.
Each year, at the beginning of the lunar new year, a festival in the village of De'e, featuring the music and dance of the various ethnic groups who live in the area, is held.
86,000 Miao reside in Longlin County, making up 24.5% of the total population. The Miao of Longlin County are found in the townships of De'e 德峨、Shechang 蛇场、Kechang 克长、Changfa 长发、Zhuchang 猪场、 and Changme 常么.
3,400 Yi (autonym: ŋo33 phu21) reside in Longlin County, mostly in De'e Township 德峨乡. In De'e Township 德峨乡, Yi are found in Agao 阿稿、Nadi 那地、Nongbao 弄保、Tangshi 塘石、and 10 other villages. Yi are also found scattered across various villages in the townships of Changfa 长发、Zhelang 者浪、Kechang 克长、Yancha 岩茶、and Zhuchang 猪场.
300 Hagei Gelao (also Pipao Gelao 披袍仡佬 or Shuiniu Gelao 水牛仡佬) and 500 Duoluo Gelao (also Daya Gelao 打牙仡佬 or Huangniu Gelao 黄牛仡佬) reside in Longlin County. The Gelao of Longlin County are found in Sanchong 三冲 and Moji 么基 villages.