Sent to Soviet Russia to train in espionage, Gu was chosen by Zhou Enlai to lead the CCP's first intelligence service, the Central Special Branch (Chinese: 中央特科; pinyin: Zhōngyāng Tè Kē).

"[1][2] Early in his life, Gu worked at Nanyang Tobacco Factory, where he became an active participant of workers' movement, then of the Shanghai Trade Union and finally of the CCP.

[1][2] In 1927, after the 12 April Incident, he became an active member of the underground communist movement together with Zhou Enlai, held numerous posts and finally became the Head of the Chinese Politburo's security service.

After the arrest he was persuaded to defect, thus causing the execution of several thousand communists over the next three months (according to the estimation of the French intelligence bureau in Shanghai).

[3] As retribution, members of his family were killed, except his young daughter Gu Liqun (顾立群) and nephew Zhang Changgeng (张长庚), allegedly on the orders of Zhou.