The incident occurred Sunday morning after dozens of members of the church assembled at a public plaza to pray, The New York Times reported. Shouwang means for watchtower.
They were put in buses, the report said. Police had also stopped church leaders in their homes following an announcement on the Internet. A Times photographer, who was later released, was also arrested.
The action comes a week after Shouwang, one of the largest churches operating out of homes with about 1,000 members, was evicted by a landlord who had been told not to renew the church's lease, the report said.
Until recently, China's religious authorities have been tolerating such unregistered churches. Lately, however, authorities have given them the choice of either breaking up or becoming part of state-run congregations.
The Times said China currently has about 60 million Protestants, with many of them opting for house-churches.
China has been cracking down on various forms of dissent lately, including imprisoning lawyers, writers and activists.
Last week, authorities detained government critic and well-known artist Ai Weiwei on suspicion of committing unexplained "economic crimes."
In the Sunday incident, the detained church members were taken to a nearby elementary school, where they were briefly questioned and photographed, the report said.