At a campaign event in New Hampshire on Saturday, Clinton said the US must be "fully vigilant" about China's military, adding that Beijing had stolen commercial secrets from defense contractors and "huge amounts of government information".
Beijing has in the past expressed outrage over US government claims it engages in state-sponsored hacking of commercial information, saying China is itself a victim of hacking attacks.
Asked about Clinton's remarks, Chinese Foreign Ministry spokeswoman Hua Chunying said the two sides had taken a "constructive spirit" in tackling the issue, Reuters reported.
"China and the US have taken a constructive spirit and approach to strengthening dialogue and cooperation to jointly face various challenges in line with the interests of both sides in a way that is conducive to peace and prosperity in the region and the world," Hua told a regular news briefing.
Clinton is the front-runner to win the Democratic nomination for the November 2016 presidential election.
In the most recent case involving suspicions of Chinese hacking, Obama administration officials have said China is the top suspect in the massive hacking of a US government agency that compromised the personnel records of at least 4.2 million current and former government workers.
China has denied hacking into the computers of the US Office of Personnel Management.