The 17th Central Committee of the Communist Party of China (CPC) opened its fifth plenary session in Beijing Friday to discuss the nation's next five-year development plan.

The four-day meeting will review proposals for the country's 12th five-year program (2011-2015) on national economic and social development.

The period would be critical for building a moderately prosperous society, the Political Bureau of the CPC Central Committee announced last month.

It would be a time of difficult issues for deepening the reform and opening-up process while accelerating the transformation of the nation's economic development pattern, said the announcement.

China has pledged to build a "xiaokang" -- moderately prosperous -- society in the first two decades of the 21st century.

"The next five-year program will be vital for dealing with difficulties to realize the objective by 2020," said Prof. Hu Angang, a prominent expert on China's national situation in Beijing.

"The new program will basically be in accordance with the principles of Scientific Outlook on Development," Hu said.

Despite of high GDP growth for years, China still faces huge challenges in development, ranging from unbalanced economic growth pattern, widening gap between urban and rural areas and between different regions, to environmental problems as well as international trade protectionism.

"China's export-driven economic growth is unsustainable," said Justin Yifu Lin, World Bank Chief Economist and Senior Vice President.

"Transformation of the country's economic growth pattern should still be a major issue for the next five years, 15 years and even a longer period of time."

The CPC Central Committee Political Bureau said in a last month's statement that transformation of the economic growth pattern should be based on improving people's livelihoods.

President Hu Jintao has pledged to adopt "Inclusive Growth," a concept created and advocated by Asian Development Bank in 2007, for resolving social problems as a result of economic development.

According to Hu, inclusive growth means to spread the benefits of economic globalization and development among all countries, regions and people and to realize balanced economic and social progress through sustainable development.

World Bank President Robert Zoellick said developing countries will play a more important role in balancing and stabilizing the world economy, and China's effort will be of great significance for restructuring the world economy after global downturn.

A draft version of the proposals for the 12th five-year program has been offered to some delegates of the CPC's 17th National Congress and organizations outside the Party.

The document was further revised based on their suggestions.

Sources with the CPC said the proposals, accumulated from throughout the Party and other organizations, would become a guideline document for China's continued reform and opening-up process as well as socialist modernization.