SHANGHAI - The "Shanghai Tower," which is currently under construction in the eastern metropolis of Shanghai and will stand as China's tallest building upon completion, reached 303.5 meters on Tuesday.

The Shanghai Tower under construction on May 28, 2012. [Photo/Xinhua]

Workers poured concrete on the 65th floor of the building, which will eventually feature 121 stories and reach a height of 632 meters.

Upon its scheduled completion in 2015, the Shanghai World Financial Center will be the tallest skyscraper in China's mainland and the world's second-tallest building, after the Burj Khalifa in Dubai.

A spokesman with Shanghai Construction Group, the construction company working on the project, said the company plans to finish pouring concrete up to the 86th floor of the building by the end of this year, when the building will reach 403 meters.

Construction of the building began in 2008. Seated in the commercial center of Lujiazui in Pudong New Area, the forthcoming landmark building overlooking the Huangpu River covers 381,600 square meters. The 100th floor of the building has been designed as an observatory, which, at 474 meters above ground, will make it the tallest of its kind in the world.