Zhang is a law graduate from China University of Political Science and Law. In 2003, together with Xu Zhiyong he established Yang Guang Xian Zheng She Hui Ke Xue Yan Jiu Zhong Xin which is now known as Open Constitution Initiative (OCI). In 2007, he participated in a petitioning on the abolishment of labour reform. In June 2008, he was warned and abstained from meeting with the incoming visitors from the Congressional Human Rights Caucus.
Criminal defense and commercial law
2010 Chou Yinghong case
2004 Lin Zhangwang case
2003 Sun Dawu case