Commentator Nguyen Quang Lap was arrested at his house in Ho Chi Minh City today afternoon, his wife told AFP.
"More than a dozen security people searched our residence for several hours and took him away," Ho Thi Hong said.
"They said his blog ran articles against the (communist) party's policies and guidelines," she added.
Lap, 58, a member of the official Vietnam Writers' Association, is a well known figure in the southeast Asian nation. His blog has received million of hits while his Facebook account has nearly 15,000 followers.
Many of the posts were strongly anti-China, reflecting widespread animosity among many Vietnamese, including intellectuals, for the country's northern neighbour.
Hanoi and Beijing are currently locked in a long-standing territorial dispute over fishing rights and island chains in the South China Sea.
Vietnam's authoritarian rulers are sensitive to any criticism of their handling of the dispute, and have routinely broken up anti-China demonstrations and arrested organisers.
Vietnam bans private media while all newspapers and television channels are state-run.
Lap's arrest is the second time a prominent blogger has been arrested this month.
Last Saturday police in Ho Chi Minh took 65-year-old blogger Hong Le Tho into custody on similar charges.
One well-known blogger, Anh Ba Sam, is currently in detention awaiting trial, while anti-China activist Bui Thi Minh Hang is awaiting an appeal hearing to challenge a three-year prison term handed out in August this year.
According to Reporters Without Borders, Vietnam is currently holding at least 34 bloggers in prison.