After a rollicking 2009, China's property developers are preparing for a return to earth.

The latest news from China Vanke, China's largest real-estate developer by market share, has set the tone. Reporting a 32% rise in net profit last year, it forecast a mixed picture this year, with selling prices likely to 'stabilize.'

That could prove to be quite a euphemism.

China's leaders, who gather this week for the annual National People's Congress, are worried about the fast rise in property prices recently. A particular concern is that many hopeful first-time buyers are being priced out of the market. Administrative measures to slow things down came into force over the winter and more could be in store.

The stakes are higher for some property companies than for others. Standard & Poor's, in a recent report, said the most at risk are companies that bought land at high prices last year. Shanghai Zendai Property and Greentown China Holdings are two vulnerable stocks here, it says. By contrast, some property businesses have proved they are more able to keep sales buoyant even in a tougher market.

Citi Investment Research points to China Overseas Land & Investment, China Resources Land and Shimao Property as examples of companies able to keep selling during the last downturn in 2008, because of what it calls their 'strong execution ability.'

This year looks set to help separate the sheep from the goats in China's property sector. The people's congress could help define just how quickly this separation happens.