"We have noticed the effort that both the United States and Iran have recently made to improve their relationship,", Foreign Ministry spokesman Hong Lei told a media briefing here.
Obama and Rouhani had a phone conversation on Friday, which was the first talk between the two countries' heads of state since the outbreak of the Tehran hostage crisis following the Iranian Revolution, over 30 years ago.
Hong said the recent development in US-Iran relations was conducive to advancing the political process for settling the crisis over Iran's controversial nuclear programme and other hot-spot issues.
"This is positive for maintaining and promoting regional peace and stability," Hong said.
China has a firm stance on a peaceful settlement to the Iranian nuclear issue through dialogue and is part of the international dialogue with Iran, which also includes Britain, France, Russia, the United States and Germany, Hong said.