From the Jamestown Foundation’s China Brief:
After China joined the UN in 1971, it adamantly opposed peacekeeping operations (PKO) and refused to contribute money or resources to any operations. Adhering to a strict definition of sovereignty and non-interference, China rejected international interventions that supposedly violated their notions of peaceful co-existence and potentially invited international scrutiny into China’s own domestic affairs. However, in 1988 China joined the special committee on peacekeeping operations, and sent its first military observers the following year and the first company of engineers to Cambodia in April 1992. Since then, China’s participation in UN peacekeeping operations has dramatically expanded by type and numbers of personnel and location of missions. This year, China is planning to send more than 400 military engineering, medical and transport teams, as well as military observers, civil policemen and political officials to join the UN peacekeeping mission in Sudan.
