"Chinese investors are very welcome in France," said the French premier after holding talks with Chinese Premier Li Keqiang at the Great Hall of the People in Beijing.
France, which is struggling with weak growth and record high unemployment, imports two and a half times as much from China as flows in the opposite direction. In 2013, Paris ran a 26 billion euro ($29 billion) deficit with the Asian giant.
Earlier in the first day of his three-day trip, Valls said that rebalancing the relationship would "depend on a greater reciprocity in our commercial relations". China's overall trade surplus rocketed by almost 50 percent last year to a record $382 billion, the government announced earlier this month, but Li said that China "never seeks trade surpluses".
"On the contrary, we hope for trade to be balanced because that is the only way to ensure the sustainable development of commercial relations."
The two oversaw the signing of 11 agreements, including a co-operation pact between Electricite de France and China General Nuclear Power Corp on reactor design, and a 30 million euro loan from France for works in a park in Shanxi province.
But while a substantial French business delegation accompanied Valls -- and despite his assurances to Chinese media that France was "more open than ever towards China, Chinese investors, students and tourists" -- no major commercial contracts were announced.
The visit comes as France and China celebrate 50 years of diplomatic relations.
It also comes ahead of a key UN Climate Change Conference in Paris later this year, where it is hoped a universal and legally binding agreement can be forged. Valls said China, the world's biggest polluter, took the issue of global warming "very seriously and is determined to act".
Li said: "We have already done a lot to fight warming and we will continue to make difficult and strenuous efforts." When US President Barack Obama visited in November China announced a target for its carbon emissions to peak "around 2030".