A new metro line linking Shenzhen airport with the city's downtown is scheduled to start operating in June, Shenzhen Metro said on Wednesday.
Workers are now testing signals on the 52-kilometer line, the company said.
The metro line will have 18 stations.
The line is designated as an airport express line serving one of China's biggest cities and a hub for hi-tech industries.
Trains on the line can run up to 120 kilometers per hour, the company said.