Addressing a news conference following the conclusion of the annual session of Chinese Parliament, Wen, who will be leaving office this year, said the country not only needs economic reform but also political structural reform, especially the reform of the leadership system of the Communist Party and the government, to uproot problems in the society, the official Xinhua news agency reported.
"Now reforms in China have come to a critical stage," Wen said, adding "without a successful political reform, it's impossible for China to fully institute economic reform and the gains we have made in these areas may be lost, and new problems that popped up in the Chinese society will not be fundamentally resolved, and such historical tragedies as the Cultural Revolution may happen again in China."
The decade-long Cultural Revolution was carried out between 1966 and 1976 under the late Communist Party Chairman Mao Zedong, to remove all capitalist elements and purge "revisionists." The revolution carried out by the Red Guard led to persecution of millions of people.
Wen said even though the party later adopted resolutions on several historical issues and brought about reforms and opening-up, the mistake of the Cultural Revolution and feudalism have yet to be fully eliminated, Xinhua reported.
"The reform can only go forward and must not stand still, less go backwards because that offers no way out," Wen said.
The premier said he has addressed the topic of political structural reform in China on several previous occasions, adding his interest in political reforms comes from "a strong sense of responsibility."
Wen's warning comes at time when China, despite its booming economy, faces growing income disparity and official corruption. All these are problems that could aggravate public discontent which in turn could threaten the Communist regime.
"I'm fully aware that to resolve these problems, we must press ahead with both economic structural reforms and political structural reforms, in particular reforms on the leadership system of the Party and the country," Wen said, adding party and government officials must fully recognize that further reform is "an urgent task" for China.
Wen said China will unswervingly implement the rural villagers' self-governance system and protect their legitimate rights of direct election.
At the parliamentary session, Wen lowered China's growth target for 2012 to 7.5 percent, the first such change after seven years at 8 percent. His announcement was in keeping with the government's goal of making economic progress while maintaining stability.
China will go through a leadership transition this year, which happens once every 10 years.
Current Vice President Xi Jingping is expected to be the successor to Hu Jintao as president and general secretary of the Communist Party, while Li Keqiang is expected to take over from Wen.