The cyber watchdog did not offer more details on the investigation.
Didi said it plans to conduct a comprehensive examination of cybersecurity risks and will fully cooperate with the relevant government authority.
The review comes just two days after the SoftBank-backed company’s blockbuster New York market debut, in what was the biggest U.S. listing by a Chinese company since 2014.
Didi, which is also backed by technology investment giants Alibaba, Tencent and Uber, was founded in 2012 by Cheng Wei as Didi Dache, a taxi-hailing app. It merged with peer Kuaidi Dache to become Didi Kuaidi and was later renamed Didi Chuxing.
The U.S.-listed shares of the company were down 7.9% at $15.1 in premarket trading.