The deal was signed during Chinese President Xi Jinping's three-day visit to Saudi capital Riyadh to meet top officials.
Following the meeting between Mr Xi and Saudi Arabia's King Salman and Saudi Crown Prince Mohammed bin Salman, the countries jointly reaffirmed the significance of a global stable oil market and deterring regional threats.
Mr Xi was presented with an honorary doctorate from King Saud University in Riyadh by King Salman, during a meeting on Thursday.
“The two sides held talks and exchanged views regarding ways to reinforce and develop comprehensive strategic partnership relations between the Kingdom and China and all international and regional issues of common interest,” the Saudi Press Agency reported the countries as saying.
The leaders signed a Comprehensive Strategic Partnership Agreement.
Iran urged to co-operate with IAEA
Mr Xi said his country supported the kingdom in “maintaining its security and stability and affirmed its opposition to any actions that would interfere in its internal affairs and rejects any attacks targeting civilians, civilian facilities, territories, and Saudi interests”.
Saudi Arabia and China agreed a need to strengthen co-operation to ensure Iran's nuclear programme remains peaceful.
They also called on Iran to co-operate with the International Atomic Energy Agency to “maintain the non-proliferation regime and emphasise respect for the principles of good-neighbourliness and non-interference in internal affairs of states”.
China “commended” Saudi Arabia's initiative to end the war in Yemen and praised its efforts aimed at encouraging dialogue between Yemeni parties.
“The two sides stressed the importance of supporting the Yemeni Presidential Leadership Council to enable it to perform its functions and reach a political solution to the Yemeni crisis,” they said.
On the Syrian civil war, the two leaders said efforts must intensify to reach a political solution, including restoring security and putting an end to terrorism. They also affirmed continued support for the efforts of the UN and its special envoy for Syria, Geir Pedersen.
$30 billion deals signed
Saudi state media said that bilateral deals worth about $30 billion were expected to be signed during the visit.
Enhancing communication between the two sides was highlighted during the talks especially between the government and private sectors in China and the kingdom to push for further investment opportunities.
Praising the existing trade, the two countries focused on bettering non-oil bilateral trade.
They said they are aiming to “facilitate the kingdom’s non-oil exports to China, as well as to increase the joint quality investment between the two countries”.
The two also agreed to intensify co-operation in fields including car production, water desalination, manufacturing, mining and the financial sector to “benefit from trade and investment opportunities aligned with Vision 2030 and the Belt and Road Initiative”.
China and Saudi Arabia also agreed to explore investment in petrochemicals, including projects in petrochemical conversion techniques, as well as work together on projects including electricity, photovoltaic energy and wind energy.