Guosen Securities, one of China's largest brokerages, said its president Chen Hongqiao died on Friday. It did not give the cause of his death.
Guosen said in a statement on Friday its was operating as normal and had nothing further to disclose.
Chen, 49, joined Guosen in June 2014, after he worked at Shenzhen Stock Exchange for more than a decade, according to state-run newspaper People's Daily.
Read More Citadel trading account in China suspended
In August, U.S.-based hedge fund Citadel said one of its trading accounts managed by Guosen Futures, a unit of Guosen Securities, has been restricted by the China Securities Regulatory Commission (CSRC).
Citadel did not say why its account had been suspended, but a source familiar with the matter said the CSRC was looking at its role in causing market volatility, in particular the number of its cancelled transactions.
The Chinese securities regulator has cracked down on trading strategies such as short-selling after turmoil in China's stock markets which wiped trillions of dollars off the Shanghai and Shenzhen stock exchanges.