A draft of the document, seen by the BBC, stresses the “highest political commitment” to implement the deal.
It will be widely seen as a rebuff to the US, as President Trump prepares to announce on Thursday if the US is withdrawing from the accord.
The joint statement will be published on Friday after a summit in Brussels.
For more than a year, Chinese and EU officials have been working behind the scenes to agree a joint statement on climate change and clean energy.
The document highlights the dangers posed by rising temperatures, “as a national security issue and multiplying factor of social and political fragility,” while pointing out that the transition to clean energy creates jobs and economic growth.
“The EU and China consider the Paris agreement as an historic achievement further accelerating the irreversible global low greenhouse gas emission and climate resilient development,” the draft document says.
“The Paris Agreement is proof that with shared political will and mutual trust, multilateralism can succeed in building fair and effective solutions to the most critical global problems of our time. The EU and China underline their highest political commitment to the effective implementation of the Paris Agreement in all its aspects.”
Both sides say they will step up action to and “forge ahead with further policies and measures” to implement their national plans on cutting carbon. Significantly, both the EU and China agree that they will outline their long term low carbon strategies by 2020.