The Foreign Ministry of China said on Friday that it had imposed sanctions on Pelosi and her family.
The visit by Pelosi to Taiwan was highly controversial. According to the Council on Foreign Relations, Taiwan has been governed independently since 1949.
The U.S. official decided to go ahead with Pelosi's trip despite China's opposition.
Speaker of the U.S. House of Representatives Nancy Pelosi wanted to visit China's Taiwan region. China's internal affairs are interfered with by this. It gravely undermines China's sovereignty and territorial integrity, seriously undermines the one-China principle, and threatens peace and stability in the Taiwan Strait.
They said that China would impose sanctions on Pelosi and her family in accordance with the laws of the People's Republic of China.
The statement didn't say anything about the nature of the sanctions.
Political analysts warn that Pelosi's visit to Taiwan could cause more tension between the U.S. and China. The relationship has been strained over issues such as Taiwan and the world economy.
In a phone call last month, the leader of China told the president not to fire at Taiwan. The White House said in a statement that the U.S. policy had not changed and that it was opposed to changing the status quo.
Pelosi is the highest ranking official to visit the island in 25 years. Some U.S.Lawmakers questioned the timing of her visit.
Pelosi said that Taiwan is an emblem of democracy and a model for the region during her trip.
China has been conducting its largest-ever military drills near the island to protest Pelosi's visit to Taiwan.
The Taiwanese defense officials said that the exercises are highly provocative and that they are watching the moves.