Yet another risk is the massive debt of local governments that rely on land as collateral. If there's a setback in the property market and land values decline, it's unclear how local governments can repay their debt, analysts said.

As of June 30 last year, that debt stood at an estimated 17.9 trillion yuan.

"People always say China's economic growth model is export- and investment-driven. But if you look at the data for the past two or three years, it is becoming solely investment-driven.

"Exports in 2012 made a negative contribution to GDP growth, and if you deduct speculative funds disguised as trade payments, you'll find that exports were a drag on growth again in 2013," he said.

As the economy increasingly relies almost solely on investment, any slowdown in investment could curtail growth.

In the first eight months of 2013, fixed-asset investment grew 20.3 percent. The pace of growth then decelerated throughout the remaining months, slowing to 19.6 percent for the full year.

Based on these figures, CASS has already lowered its forecast for this year's investment growth to 19 percent, down from 20.1 percent just a month ago.

Li Xuesong, deputy director of quantitative and technical economics at CASS, said the revision reflected the increasing difficulty of accessing money while the central government puts "curbing local government debt" as a priority for 2014.

Local governments have fallen in line with this call: As of last month, half of the provincial-level regions had cut their investment growth target for this year below 18 percent.