Hong Le Tho, 65, was arrested in Ho Chi Minh City on Saturday for posting articles "with bad content and incorrect information that reduce trust in state agencies", the Ministry of Public Security said in a statement released late Saturday.
Tho's blog, called 'Nguoi Lot Gach' -- literally 'a brick layer' has run for at least three years and was regularly updated in Vietnamese, English and French with his commentary on social and political issues in Vietnam.
Hanoi and Beijing are 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.
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Tho's blog has been inaccessible since he was arrested.
Vietnam bans private media while all newspapers and television channels are state-run. Lawyers, bloggers and activists are regularly subject to arbitrary arrest and detention.
According to Reporters Without Borders, Vietnam is currently holding at least 34 bloggers in prison.
This year, Vietnam released several high-profile dissidents, including Nguyen Van Hai, whose case had been raised by US President Barack Obama, and lawyer Cu Huy Ha Vu.
Both men now live in exile in the US.
Analysts say the releases were part of a drive to strengthen ties to former wartime foe America amid the simmering maritime dispute with China.
Vietnam, a one-party state, is regularly denounced by rights groups and Western governments for its intolerance of political dissent.