That's according to a report in the Wall Street Journal on Sunday (January 14).
The hold-up comes after the mid-air blowout of a panel on an Alaska Airlines MAX 9 earlier this month.
China Southern Airlines was ready to receive related but not identical planes in January.
Now the Journal reported it plans to conduct more safety inspections on the aircraft.
The report further said China's aviation regulator told airlines to conduct precautionary safety inspections on their MAX jets.
Chinese airlines do not use the MAX 9 model.
The MAX 8 jets they operate lack the panel involved in the Alaska Airlines incident.
The Journal reported Beijing is holding off from making further big moves as it waits for more clarity from U.S. investigations into the accident.
Boeing declined to comment.
China Southern Airlines and Chinese regulators did not immediately respond to Reuters' requests for comment.
China suspended most orders and deliveries of Boeing planes in 2019.
That followed the worldwide grounding of the 737 MAX after two fatal crashes.
