"The increase in flight frequency between Vietnam and China highlights effective pandemic prevention and is a positive sign for the recovery of the Chinese aviation market," the Civil Aviation Authority of Vietnam said on its website.
China is one of the few countries in the world still pursuing a zero-Covid policy with stringent entry requirements.
Earlier, the Chinese government only allowed carriers of both countries to operate one flight a week.
Vietnam resumed regular flights from Jan. 1 and lifted all Covid restrictions on international flights from Feb. 15.
Before the pandemic, China was Vietnam's biggest tourism market with nearly 4.8 million Chinese visiting in 2019.
Aviation officials expect the number of international passengers going through Vietnamese airports this year to reach 10 million, or around 24 percent of pre-pandemic levels. Of these, the country expects to draw five million foreign tourists.