Following the abortive Hundred Days' Reform in 1898, Zheng left his post in Beijing and took up a number of important government positions in central and southern China.

Instead, he withdrew from public life entirely and retired comfortably in Shanghai, where he devoted his time to calligraphy, poetry and art, while also writing extensive articles critical of the Kuomintang leadership, whom he characterized as “thieves”.

[citation needed] Zheng became a close adviser of Puyi and helped arrange for his flight to the foreign concession at Tianjin after his expulsion from the Forbidden City by General Feng Yuxiang.

Zheng remained loyal to the throne and secretly met with Japanese officials and groups such as the Black Dragon Society to discuss a restoration of the Qing dynasty in Manchuria.

Following the Mukden Incident and the invasion of Manchuria by the Imperial Japanese Army in 1931, Zheng played an important role in the establishment of Manchukuo, becoming its first prime minister the following year.