There are conflicting news about this hot topic. The initial news, according to Hexun, the Chinese tax bureau is going to collect tax on the gains made from stocks and real estate for people earn more than 120,000 Yuan per year. Note in China 120,000 Yuan is the threshold for people to file personal income tax.
My take: the personal income tax and especially the filing of personal income tax (for person earn over 120,000) are still fairly new. The Chinese stock market is also fairly new (compared to western markets). It IS good for China to align the tax system, encourage investing (in stocks) while keep the fairness of society (people from different income level). But keep this balance and how to accurately calculating taxes will NOT be easy for the goverment, and brokage firms.
On the other hand, amid the recent bubble (speculation) in Chinese stock and housing market, the regulators can use tax policy to contain the speculation. They have already done so with the stamp tax increase on May 31 this year.