It also means that in that time, A shares will also have considerable weightings in international indexes such as MSCI Emerging Market, Chen said.

In fact, the changes may come faster. Several stock analysts and fund managers have told China Daily that they believe MSCI, the world's most influential index provider, may include A shares into its Emerging Markets Index as early as 2016, and that would directly cause a catch-up in A-share allocation by global investors.

Around $1.4 trillion are benchmarked against MSCI's Emerging Markets Index, according to Reuters data.

China's A-share market, suffering from depressed valuations for years, showed very definite signs of a rebound in 2014. The benchmark Shanghai Composite Index had rallied more than 50 percent so far since last year, a lure surely for international investors.

"The rally we're seeing right now is unprecedented, even including 2007's bull run. Even though the rebound has been very sharp, if you look at the overall market valuation, it's still about 14 times, compared to 2007 when it was 60-70 times. When people say we're taking on excessive risk, it isn't true because the market is still cheap in China," said Hong Hao, managing director of research at BOCOM International.

Some investors are simply using Qualified Foreign Institutional Investor and Renminbi Qualified Foreign Institutional Investor schemes to tap the lucrative mainland market.

During January-November 2014, a 140 billion yuan RQFII quota and $16 billion QFII quota were granted, plus a 150 billion yuan quota under the interbank bond market direct access program.

Linan Liu, greater China rates strategist at Deutsche Bank, said in a recent research note that the bank believes another stock connect scheme between the Shenzhen and Hong Kong bourses will be launched in the second half of 2015, with roughly half of the quota of the Shanghai-Hong Kong Stock Connect program.