Unit 731 was a top-secret biological and chemical warfare research base established in Harbin in 1935.

731部队于1935年建在今黑龙江省哈尔滨市平房区。

Unit 731 was a top-secret biological and chemical warfare research base established in Harbin as the nerve center for Japanese biological warfare in China and Southeast Asia during World War II.

731部队是日军在哈尔滨建立的高度保密的生物战和化学战研究基地，是二战期间，日军使用生物战打击中国和东南亚的神经中枢。