Sharif, previously elected prime minister in 1990 and 1997, has been a frequent visitor to China and believes China is Pakistan's "most reliable friend".
He is making the first stop on his first foreign trip since being elected in May. Sharif met Li during Li's visit to Pakistan in late May, before Sharif was formally sworn in.
At the start of his meeting with Li on Friday, Sharif said the warm welcome he received reminded him of the saying "Our friendship is higher than the Himalayas and deeper than the deepest sea in the world, and sweeter than honey."
Li and Sharif agreed to upgrade the China-Pakistan free trade area and deepen anti-terror cooperation.
Sharif promised that Pakistan will do its best to protect Chinese citizens in the country. Two Chinese were killed in Pakistan-administered Kashmir by Taliban terrorists on June 23.
The prime minister enjoyed a subway trip in Beijing on Thursday afternoon and he planned to take a bullet train to Shanghai on Friday.
He told China Daily that he is "very much looking forward to" introducing Chinese trains to his country.
The main objective of the ride is to explore the possibility of having similar high-speed trains in Pakistan, he said.
"It is going to be a tremendous experience," he said.
He is also scheduled to meet the leaders of many major Chinese enterprises, especially in the infrastructure construction and energy sectors.
Hu Shisheng, a researcher on South Asian studies at the China Institutes of Contemporary International Relations, said infrastructure construction and energy scarcity are the two biggest problems for Pakistan's economy.
"China and Pakistan have enjoyed very strong political and military ties. Now they are building up in the economic field," Hu said, adding that economic issues are the theme of Sharif's political agenda.
People enjoy time at old teahouse in Kashgar, NW China's Xinjiang