US Seismologist Youlin Chen Detained in China Over Espionage Claims

Chinese‑born American seismologist Youlin Chen, 54, was arrested at Beijing Capital International Airport on 5 November 2024 while returning from a family visit. He has been held for nearly two years without trial and faces espionage charges linked to his research on detecting underground nuclear tests, including those conducted by North Korea. Chen’s work was funded by U.S. agencies such as the State Department and the Air Force Research Laboratory and was publicly published.

His wife, seismologist Yufang Rong, says he has been interrogated more than 100 times, denied access to a lawyer for the first 13 months, and has suffered serious health problems, losing up to 40 lb and lacking adequate medication for diabetes, high blood pressure and cholesterol. Rong told Reuters, “I believe they will convict him no matter what and the trial will be behind closed doors.”

The U.S. State Department designated Chen “wrongfully detained” in March 2025, with Secretary of State Marco Rubio and President Donald Trump raising the case with Chinese leader Xi Jinping during a May state visit, but Beijing has taken no action. A Chinese foreign‑ministry spokesperson said the case is being handled “in accordance with the law” and denied any wrongful detention. Advocacy groups Global Reach and the Foley Foundation argue that the detention may be linked to China’s interest in Chen’s expertise for concealing nuclear tests.