Project 596 (Miss Qiu, Chinese: 邱小姐; pinyin: Qiū Xiǎojiě, as the callsign; Chic-1 by the US intelligence agencies) was the first nuclear test of the nuclear weapons program of China, detonated on 16 October 1964, at the Lop Nur test site in Xinjiang. It was an implosion fission device containing about 15 kg weapons-grade uranium (U-235), produced at the Lanzhou enrichment plant.

It had a yield of 22 kilotons, comparable to the Soviet Union's first nuclear bomb RDS-1 in 1949 and the American Fat Man bomb dropped on Nagasaki, Japan in 1945. Key figures in the device's design included Deng Jiaxian, Qian Sanqiang, and Peng Huanwu. With the test, China became the world's fifth nuclear-armed state. This was the first of 45 successful nuclear tests China conducted between 1964 and 1996, all of which occurred at the Lop Nur test site. The atomic bomb is now honored under China's "Two Bombs, One Satellite".

Premier Zhou Enlai announced the test the same day, during which he criticized US "nuclear blackmail" and the 1963 Partial Nuclear Test Ban Treaty as imposing a "nuclear monopoly". A key moment in the history of the People's Republic, the test influenced the ultimate UN recognition of the mainland seven years later, and China's advance towards a superpower. US leadership had previously decided against military strikes on nuclear facilities in China; following the test its espionage against the program was enhanced. The test caused the government of Taiwan under Chiang Kai-shek to pursue its own clandestine nuclear weapons until 1988. Relations with the Soviet Union, which had turned hostile since 1961, worsened after the test; tensions briefly approached nuclear war in 1969.