Bo Yibo
In the autumn of 1932, Zhang was arrested in Xingtai by the Kuomintang (KMT) government, and imprisoned at the Caolanzi Prison in Beiping (now Beijing) for more than four years. Also held in the prison were other important Communist leaders including Bo Yibo, An Ziwen, and Liu Lantao. In 1934, Zhang joined the Communist Party of China while in prison. In 1935, the KMT government signed the He–Umezu Agreement with Japan, agreeing to cease all KMT activities in Hebei, including Beiping, and released the Communist prisoners in Beiping the following year.