Miners should be cautious now that China's economic growth may not be stable for longer periods.

Several economists forecasts that the pace of China's growth may have a fallout until it tries to perform better.

The shipyard, Waigaoquai Shipyard, has put China and Australia through the world economic crisis. The shipyard has successfully employed 20,000 and produces new megaship every two eeks.

However, chief engineer Tao Ying knows the existing problems on overcapacity in his industry. He said the many ships nowadays are being build for the international market.

“If the world's economy keeps on going down, our overcapacity will become huge,” he said.

“Some enterprises might withdraw from the market and stop making ships altogether."

Earlier forecasts on China relying on exports has led to Australians to think that the demand for raw materials will last longer. Still, Professor Michael Pettis of Peking University commented that demand may be reduced at some point.

"I would say there is at least a 50 per cent probability that next year will also be a very good year for growth and after that the probability of yet another year goes down quite dramatically,” he said.

Mr. Pettis added that Australian iron ore companies should not rely on its sales in the future.

“I would be even more worried than that because one of the things that has been happening is that it seems like China has been stockpiling quite a lot of commodities."

The professor said Australia and the rest of the world should worry if the Chinese economic growth slows down and there is a slight chance that stockpiles in China start selling off.

On the other hand, Trade Minister Simon Crean told a local television station that China understands that sustainability is obtained forever.

He further suggested that China needs to boost its domestic demand to escape a major downturn in production.