The Sungacha or Songacha (Russian: Сунгача Sungacha or Сунгач Sungach,^[1] Chinese: 松阿察河; pinyin: Sōngàchá Hé) is a river marking part of the border between the Russian Federation and the People's Republic of China. It is a left tributary of the Ussuri, and the only outflow of Khanka Lake.

The 180-to-210-kilometer (110 to 130 mi)-long Sungacha's length fluctuates, as the stream bed changes every year. The area of its basin is approximately 25,600 km² (9,900 sq mi), of which 21,000 km² (8,100 sq mi) within Russia.^[2]

The river supports a rich diversity of flora and fauna, including Nelumbo nucifera in its basin.

The Sungacha's waters come from rain, snow and springs.