China's top political advisor Jia Qinglin Friday asked Shanghai, the economic center of the country, to upgrade its growth pattern through technology innovation and environmental protection.

In a working tour in Shanghai, Jia, chairman of the National Committee of the Chinese People's Political Consultative Conference, said the city should use the upcoming World Expo as a "historical chance" to readjust its growth model and strive for stable and relatively fast economic growth.

The city on Thursday held the 100-day countdown for the six-month-long mega event.

Jia stressed the importance of industrial upgrading, brand marketing, research and development during visits to a shipbuilding factory of the China State Shipbuilding Corporation and the Shanghai Zhenhua Port Machinery Co. Ltd..

He was upbeat about technological innovation adopted in the building of a bridge-tunnel project linking Shanghai with Chongming Island, China's third largest island located in the estuary of the Yangtze River.

The 25.5-kilometer project, including a 8.9-kilometer tunnel that boasts the world's largest diameter of its kind, and a 16.6-kilometer bridge, was open to traffic in October last year.

Jia said the project well demonstrated how self-developed technology had been used to boost economic growth and social development.

In a visit to a bird sanctuary and a national forest park on Chongming Island, Jia also stressed the importance of sustainable development through more tree-planting efforts, resource and energy saving, and the development of low-carbon economy.