Beijing was reacting to US President Donald Trump warning Iran that the country would be finished if it attacked America.
On Sunday, a rocket from an unknown location was fired into Baghdad's Green Zone housing government offices and embassies including the US mission.
"We have taken note of the tensions that recently occurred in the Gulf region. China talked to the US. Our State Counsellor Wang Yi talked to US Defence Secretary Mike Pompeo on the phone," Chinese Foreign Ministry spokesperson Lu Kang said.
Asked if Beijing was concerned over the rising tensions, Lu said: "Of course, tensions in the region serve no country's interest and do not do any good to the global economy.
"Of course we are concerned and that's why we are contacting all relevant parties and asked them to exercise restraint and jointly find a proper resolution," Lu added.
Ties between Iran and the US have gone south after the US pulled out of a nuclear pact last year and reimposed sanctions on the Islamic Republic.
China, the biggest importer of Iranian crude oil, has backed the country and opposed the US sanctions.
Beijing has deep trade relations with Tehran but it also maintains good ties with Iran's arch rival Saudi Arabia.