The five years from 2011 to 2015 are a critical stage for China to build a moderately prosperous society in an all-round way, the Central Committee of the ruling Communist Party of China (CPC) said Monday.

In setting the 12th Five-Year Plan, the CPC "must adapt to the changes of domestic and international situations and comply with the people's new expectations of living better lives," said a communique issued at the close of the Fifth Plenary Session of the 17th CPC Central Committee.

The 12th Five-Year Plan period was a time of difficult issues for deepening the reform and opening-up process and accelerating the transformation of the nation's economic development pattern, said the communique.

The Party should "take scientific development as the theme, employ the acceleration of the transformation of the economic development pattern as the main line, deepen the reform and opening-up process and safeguard and improve the people's livelihoods, so as to lay a decisive foundation for building a moderately prosperous society," said the communique.

China is still in an important period of strategic opportunities during which there is a great deal China can achieve. The nation is "faced with both precious historic opportunities and plenty of foreseeable and unforeseeable risks and challenges," said the communique.

The communique also outlined the achievements the nation had achieved during the 11th Five-Year Plan, including fast development of social productivity, drastic enhancement of overall national strength, and remarkable improvement of living standards.