Xi's plane was escorted by eight Pakistani Air Force fighter jets when it entered the country's airspace.
Xi and his wife, Peng Liyuan, were warmly welcomed at the airport by Pakistani President Mamnoon Hussain and Prime Minister Nawaz Sharif as well as their wives.
A 21-gun salute was fired to pay respects to the distinguished Chinese guests, who were also presented with flowers by two Pakistani children dressed in traditional costume.
A grand red-carpet welcome ceremony was held at the airport, during which Pakistani children threw petals over the carpet in token of good wishes. After that, Xi, accompanied by Hussain and Sharif, inspected the honor guard while a military band played the national anthems of both countries.
Huge signboards bearing the portraits of the leaders of the two countries were seen lining the streets in Islamabad Monday.
"Pakistan-China friendship is higher than mountains, deeper than oceans, sweeter than honey, and stronger than steel," read signboards in both Chinese and English. Other slogans included "Long live the Pakistan-China friendship" and "Pakistan and China are iron friends."
In a written statement, Xi said China and Pakistan enjoy a long history of friendship, and the two countries have established an all-weather friendship and conducted all-round cooperation, bringing tangible benefits to the people of both countries and contributing to the regional peace, stability and development.
China has always viewed the bilateral relations from a strategic and long-term perspective, Xi said.
"Pakistan is the first stop of my first overseas visit this year. I'm eager to make extensive contacts with Pakistani leaders as well as people from various sectors for in-depth exchange of views on bilateral relations and international, regional issues of shared interest," the Chinese president said.
"I hope, through my visit, the two countries can consolidate the traditional friendship, deepen practical cooperation in all areas, push the strategic cooperative partnership to a new high, enrich the concept of the China-Pakistan community of shared destiny, and set an example for China to build such communities with neighboring countries," Xi said.
High on the agenda of Xi's two-day state visit also include advancing the construction of the China-Pakistan Economic Corridor, a planned network of roads, railways and energy projects linking southwest Pakistan's deepwater Gwadar Port with northwest China's Xinjiang Uygur Autonomous Region.
The two sides are scheduled to hammer out a package of deals in such fields as energy, infrastructure, trade and cultural exchange.
After Pakistan, Xi will fly to Indonesia to attend the Asian-African Summit and activities to commemorate the 60th anniversary of the Bandung Conference.