Huge losses under the Qualified Domestic Institutional Investor (QDII) scheme have Chinese investors filing complaints against the banks involved.

QDII give Chinese investors to access to foreign securities markets through commercial banks in China. But the global financial crisis led to sharp declines in many overseas stock markets, diminishing the value of financial products under the QDII scheme.

Only 5 of the 46 existing QDII products from Chinese banks saw a profit and 16 of them have lost over 50 percent of their value.

Investor complaints prompted the China Banking Association to organize a joint news conference for Industrial and Commercial Bank of China, China Construction Bank, Bank of China, Agricultural Bank of China, Bank of Communications, China Postal Savings Bank, China Merchants Bank and Standard Chartered Bank in which the eight banks pledged to better explain the risks involved with QDII.

"We have to help consumers understand that 'expected returns' doesn't mean a product will always generate profit. We have to do a better job explaining such terms to our customers when selling our financial products," said Sun Dawei, a representative from Bank of China.

But it's more important to teach consumers how to invest reasonably, said Wilson Chia, head of consumer banking at Standard Chartered Bank in China.

"I advise consumers to always have cash when the markets get rough. Liquidity is important. And before you buy a product, you have to do thorough research and understand your choices. Too many people just listen to their friends, buy low and hope for the price to go up. I would suggest consumers not try to speculate," said Chia.

Some QDII products may still be good investments according to the latest report from Benefit Wealth. An Agricultural Bank of China product was the best QDII with an over-12-month term, turning a 26.31 percent profit.