In the stock market, a "circuit breaker" to suspend trading in the event of wide price swings backfired and fueled steeper falls.
It was withdrawn after just four days. That followed complaints curbs on stock sales and other emergency measures imposed to stop last year's market plunge were clumsy and fueled investor panic.
In currency markets, Beijing has struggled to squelch expectations it plans to devalue the yuan. That has forced the government to spend tens of billions of dollars to defend the exchange rate.
Last year's economic growth, due to be reported next week, is forecast to have slowed to 7 per cent or below. That still would be the world's second-highest, surpassed only by India, which is one-tenth China's size.
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And the latest turmoil has a political tinge because it comes as Beijing is promoting a bigger role for itself as a regional military power and in managing international trade and finance.
The Communist Party under President Xi Jinping wants the prosperity that comes from free-market competition and has promised entrepreneurs a bigger role in the state-dominated economy.
Forecasters who expect China to keep growing at a healthy rate "pinned that expectation on a belief that market forces will be given greater play," said Mark Williams, chief Asia economist for Capital Economics.
The party has won praise for making it easier to start and run a private business. But it has yet to act on what the World Bank and other reform advocates say is the most pressing issue: Cutting monopolies and other privileges of state companies that control industries and are a drag on China's steadily slowing economic growth.
Williams, of Capital Economics, points to the counter-example of India, where RBI Governor Raghuram Rajan is credited with cooling inflation since 2013 with a strategy that included talking in detail about his goals.
"There is a much greater sense of trust among businesses and households toward the (Indian) central bank," said Williams, "and we just don't see that at all in China.