Chinese President Xi Jinping arrived in Saudi Arabia on Tuesday, the first stop on a trip to raise the economic giant's political profile in a troubled Middle East.
Xi, making his first presidential visit to the region, will also travel to Egypt and Iran during his five-day tour.
State television showed Xi meeting with King Salman and the official Saudi Press Agency said the monarch held a luncheon banquet in his honour.
The two sides signed 14 agreements and memoranda of understanding, many of them on economic issues.
One dealt with establishing a mechanism for consultations on fighting "terrorism," while another foresaw cooperation on building a nuclear reactor, SPA said.
"Since China and Saudi Arabia forged diplomatic ties 26 years ago, our relationship has developed by leaps and bounds, with mutual political trust deepening continuously and rich results in cooperation in various fields," Xi said in written remarks, cited by China's official Xinhua news agency.
Xi said he foresaw a fruitful visit "conducive to lifting our cooperation in various fields to a new level and to elevating the collective cooperation between China and GCC nations."
He was referring to the six-nation Gulf Cooperation Council to which Saudi Arabia belongs.
On Wednesday, Xi is to join Salman for a ceremony to inaugurate an energy research centre in Riyadh.
And they will also open, remotely from the capital, a refinery on the kingdom's Gulf coast. The refinery is a joint venture between state-owned Saudi Aramco and China Petrochemical Corp.
Red flags of China are flying in central Riyadh for the high-profile visit, to which the Arab News daily devoted a 10-page special supplement.
Tensions between regional powerhouses Saudi Arabia and Iran reached a new high this month when Riyadh and a number of its Sunni Arab allies cut diplomatic ties with Tehran.
They acted after protesters burned Saudi diplomatic missions in Iran following the kingdom's January 2 execution of Shiite cleric Nimr al-Nimr.
He was among 47 people put to death in a single day for "terrorism". Most of those executed were Sunnis.
- Seeking stability -
Signup to our newsletter and follow us on Facebook and Twitter!
"The kingdom and China both work towards world stability, peace and security. And the kingdom appreciates your efforts towards this," Salman told Xi, according to SPA.
Both Saudi Arabia and China maintain tight control on civil society and have been criticised by rights activists.
Xi arrived three days after a historic international deal lifted sanctions on Iran in return for a scaling back of its nuclear capabilities.
China and five other world powers helped broker that agreement. But Riyadh fears it will further embolden Iran, which it accuses of interference in Yemen, Syria and elsewhere.
Last week a Chinese diplomat urged "calm and restraint" between Saudi Arabia and Iran, but the foreign ministry in Riyadh late Tuesday issued a 58-point complaint accusing Iran of "sedition, unrest and chaos" over nearly four decades.
"Clearly now there are tensions between Saudi Arabia and Iran, so he (Xi) will be going there in the role of persuader," Zhu Feng, professor at Peking University's School of International Studies, told AFP before the visit.
"China will try and do what it can, but it still won't play a main role."
In the past month, Beijing hosted high-level members from both the Syrian regime and its opposition.
China has consistently urged a "political solution" to the Syrian war, despite being seen as sympathetic to President Bashar al-Assad.
Iran is one of Assad's main allies while Saudi Arabia backs rebel forces.
In December Riyadh hosted an unprecedented meeting of the Syrian opposition aiming for unity before peace negotiations sought with Assad's regime.
The United Nations hopes those talks will begin in Geneva on January 25.
"China is the biggest importer of Middle Eastern oil," Zhu said. "So stability in the Middle East is what China would most like to see."
Riyadh has been deepening ties with major powers beyond its traditional ally Washington, which it sees as insufficiently engaged, particularly in the face of alleged Iranian interference.
Xi's predecessor Hu Jintao visited the kingdom in 2009.