Lo Van Duc, 33, of Ky Son District of Nghe An Province, is now under investigation for "human trafficking," the district police said Thursday.
Duc said when doing business in China in 2015, he met a Vietnamese woman named Tu, who remained unidentified.
She suggested he find Vietnamese women to bring to China to sell as wives to Chinese men. For each woman sold, Duc would be paid VND10-20 million (US$420-840).
In 2016, Duc returned to Vietnam and met with a woman from a poor family in Ky Son. She was 21 then.
Duc told her that he could help her find a decent job in China and that he himself has a successful business there. The woman believed him and later that year he took her to Quang Ninh Province and the two crossed into China via illegal trails.
Duc and Tu then sold the woman to a Chinese man for RMB30,000 (US$4,370). Tu paid Duc VND10 million.
Late last year, the woman escaped and returned to Vietnam, where she reported Duc to the police.
It is not clear if she gave birth to any children while living with the Chinese man.
Hundreds of thousands of women from Vietnam, Cambodia, Laos, and Myanmar have been smuggled or taken to China to wed local men, activists say. Some end up happily married, but many others suffer violence and forced labor.