Kuandian Manchu Autonomous County (simplified Chinese: 宽甸满族自治县; traditional Chinese: 寬甸滿族自治縣; pinyin: Kuāndiàn Mǎnzú Zìzhìxiàn; Manchu: ᡴᡠᠸᠠᠨᡩᡳᠶᠠᠨ ᠮᠠᠨᠵᡠ ᠪᡝᠶᡝ ᡩᠠᠰᠠᠩᡤᠠ ᠰᡳᠶᠠᠨ; Möllendorff: kuwandiyan manju beye dasangga siyan), is a county of eastern Liaoning province, China, bordering North Korea to the southeast and Jilin in the northeast. It is under the administration of Dandong City, the centre of which lies 75 kilometres (47 mi) to the southwest, and is served by China National Highway 201. In Kuandian is the Hushan Great Wall, the most easterly section of the Great Wall of China. A short reconstruction of the wall is open to tourists. The area has an abandoned airstrip that was used by the Chinese airforce during the Korean War.

As of 2009, the county's population was 434,900 people.

The area of present-day Kuandian belonged to the Yan state during the Warring States period, and was then brought under the Liaodong Commandery in the Qin Dynasty.

From the Eastern Han Dynasty until 408 CE, the southern part of the county was incorporated under the rule of various Chinese dynasties. The area became part of Goguryeo in 408 CE, and afterwards became part of the Tang Dynasty's Protectorate General to Pacify the East.

The county's name originates from the Kingdom of Balhae, when the area was known as Kuandianzi (Chinese: 寬甸子).

The area would come under the reign of the Liao dynasty, then the Jin dynasty, and then the Yuan dynasty.

In 1467, the Ming Dynasty built a defensive wall in the eastern part of the region that terminated at the Yalu River. Various forts were added in 1546 and 1573.

Kuandian County was established in 1876 under Fenghuang Subprefecture (Chinese: 鳳凰廳). The area belonged to Fengtian Province [zh] (奉天省) during the early days of the Republic of China.

The county was put under the jurisdiction of the prefecture-level city of Dandong in 1965. Kuandian County was approved as an autonomous county in September 1989, becoming the Kuandian Manchu Autonomous County.

There are 19 towns, 2 townships and 1 ethnic township in the county. The county's seat of government is located in the town of Kuandian.

The county's 19 towns are: Kuandian [zh] (宽甸镇), Guanshui [zh] (灌水镇; Manchu: ᡤᡠᠸᠠᠨ ᡧᡠᡳ ᠵᡝᠨ), Penghai [zh] (硼海镇), Hongshi [zh] (红石镇), Maodianzi [zh] (毛甸子镇), Changdian [zh] (长甸镇), Yongdian [zh] (永甸镇), Taipingshao [zh] (太平哨镇; Manchu: ᡨᠠᡳ ᡦᡳᠩ ᡧᠣ ᠵᡝᠨ), Qingshangou [zh] (青山沟镇), Niumaowu [zh] (牛毛坞镇), Dachuantou [zh] (大川头镇), Qingyishan [zh] (青椅山镇; Manchu: ᠴᡳᠩ ᡳ ᡧᠠᠨ ᠵᡝᠨ), Yangmuchuan [zh] (杨木川镇), Hushan [zh] (虎山镇), Zhenjiang [zh] (振江镇), Budayuan [zh] (步达远镇), Daxicha [zh] (大西岔镇), Bahechuan [zh] (八河川镇; Manchu: ᠪᠠ ᡥᡝ ᠴᡠᠸᠠᠨ ᠵᡝᠨ), and Shuangshanzi [zh] (双山子镇).

The county's 2 townships are Shihugou Township [zh] (石湖沟乡) and Gulouzi Township [zh] (古楼子乡).

The only one ethnic township is Xialuhe Korean Ethnic Township (下露河朝鲜族乡; Korean: 하로하조선족향).

Kuandian occupies the eastern half of Dandong City and is situated among the Changbai Mountains, on the northwest (right) bank of middle-lower reaches of the Yalu River, across which it borders the North Korean provinces of North Pyongan and Chagang. Domestically, it borders Ji'an (Jilin) to the northeast, Fengcheng to the west, Benxi to the northwest, and Huanren County to the north. It has a total area of 6,193.7 km (2,391.4 sq mi) and 216.5 km (134.5 mi) of the Sino-Korean border.

Kuandian has a monsoon-influenced humid continental climate (Köppen Dwa) characterised by very warm, humid summers, due to the monsoon, and long, cold, and very dry winters, due to the Siberian anticyclone. The four seasons here are distinctive. A majority of the annual rainfall occurs in July and August. The monthly 24-hour average temperatures ranges from −11.3 °C (11.7 °F) in January to 22.6 °C (72.7 °F) in July, while the annual mean is 7.5 °C (45.5 °F). Due to the mountainous location, temperatures tend to be cooler, and summer rainfall is heavier. The average relative humidity is 71%, and the frost-free period is 140 days.

The county is majority Manchu as of 2002.

Ethnic Composition of Kuandian Manchu Autonomous County (2002)

Ethnic Group	Population	Percentage
Manchu	232,248	53.42%
Han	195,346	44.93%
Korean	4,925	1.13%
Mongols	1,562	0.35%
Hui	398	0.09%
Other	203	0.05%

Historical population

Year	Pop.	±%
1907	176,018	—
1915	197,039	+11.9%
1932	324,680	+64.8%
1940	236,748	−27.1%
1949	302,714	+27.9%
1953	294,594	−2.7%
1964	348,814	+18.4%
1982	431,096	+23.6%
1985	436,001	+1.1%
1991	444,609	+2.0%
2005	437,651	−1.6%

Population censuses in the county have been undertaken since 1907. The county's population has declined since its peak of 444,609 people in 1991.

During the People's Republic of China, the county's urban population, and proportion of people living in urban environments has grown significantly. In 1949, the year the People's Republic of China was proclaimed, 1.8% of the county's population lived in urban areas. By 1953, this rose to 4.0%. In 1982, 9.2% of the county's population lived in urban areas, which rose to 15.3% by 1985, 23.8% by 1991, and 25.5% by 1995. At 2005, 23.7% of the county's population lived in rural areas.

Kuandian's mineral deposits include boron, iron, lead, zinc, coal, copper, magnesite, and talc. The county's boron output accounts for about 50% of China's total, and the area is sometimes called "boron sea" (Chinese: 硼海; pinyin: péng hǎi).

National Highway 201 and the Tieling–Changdian Highway (Chinese: 铁长线) passes through the county. The county is also served by Fenghuangcheng–Shanghekou Railway [zh] (凤上铁路).

• Yu Zhenwu (born 1931) - pilot
• Tian Xueren (born 1947) - politician
• Zhang Jiehui (born 1957) - politician
• Zhang Shaochun (born 1958) - politician
• Zhu Yuchen (born 1961) - business executive
• Wang Qiang (1975-2005) - serial killer
• He Xiangyu (born 1986) - contemporary artist
• Jin Jingzhe (born 1963) - physician, politician