The 2010 World Expo opened in Shanghai, China, overnight with New Zealand's pavilion already proving a big hit, Dominion Post reported on Saturday.

New Zealand Commissioner-General Phillip Gibson said that, even before the opening, hundreds of people had come to touch a 12- metre-high steel and rubber pohutukawa tree which guarded the entrance to the New Zealand pavilion.

"We've had to build a barricade around it because it's been so popular," Dominion Post reported.

More than 70 million people are expected at the expo over the next six months, with 400,000 people a day expected to visit the New Zealand pavilion.

Mr Gibson said New Zealand had bagged a prime spot near the Chinese pavilion and in clear view of the millions who use one of Shanghai's main bridges.

A waka would be carved outside and an 1800kg pounamu boulder was already proving to be an attraction.

The main feature of New Zealand's $30 million pavilion -- paid for by the Government and businesses -- was a rooftop garden designed to reflect the diverse Kiwi landscape.

It included alpine mountain grasses, a bubbling mud pool, and a beautiful beach.

Beyond the scenery were business and political objectives.

"It's a great opportunity to showcase ourselves in a country that is increasingly critical to our economic wellbeing," Mr Gibson said.