Li, 57, who, along with Xi Jinping, 59, emerged as the country's top leaders within the powerful seven-member politburo standing committee during this month's Communist Party congress, spoke while chairing a conference on comprehensive reform.
Li, who will succeed Premier Wen Jiabao, vowed to deepen reform and opening up to promote scientific development and the transformation of the economic development pattern, and to achieve sustainable and healthy economic growth, the official Xinhua news agency reported.
Li, citing the country's achievements in the past 30 years of reform, promised to give further boost to reforms to improve the lives of the people.
"We are also aware that the current reforms have entered a 'fortified zone' and a 'deep-water zone'... we have to face the challenges and break all the systematic obstacles that block scientific development," Li said.
Li said reform means not only liberating the thinking or transforming mindsets, but also reshuffling interests as economic and social development would lack vitality if the interests turned rigid.
Market economy means an economy under the rule of law, he said, adding reforms should abide by laws, while mature reform experiences can turn into rules or laws to consolidate the reform achievements.
Separately, Xi, who has become the general secretary of the Communist Party's Central Committee and will succeed President Hu Jintao in March, issued a written instruction to officials asking them to give wide publicity to promote the spirit of the 18th party congress.
Xi asked the publicity teams to clearly comprehend the major theories, guidelines and policies as well as working arrangements set down at the congress, Xinhua reported.
Liu Yunshan, another member of the seven-group Standing Committee, said any publicity effort should focus on Hu Jintao's report to the congress, and Xi's recent speeches.