President Hu Jintao signed a presidential order for the immediate promulgation of the law at Monday´s session. The law became effective upon promulgation, the Chinese news agency Xinhua reports.
In underlining that it is an internal issue of China, Premier Wen Jiabao told a press conference after the vote that Beijing would never allow any foreign interference in the Taiwan issue, and insisted it was not afraid of any such interference should it occur.
"We are not willing to see that any foreign interference would occur, but we are not afraid of any interference should it occur," Wen stressed.
The Premier asserted the ten-item Anti-Secession Law was not targeted against Taiwanese, but against secessionist activities.
It reaffirms Beijing´s goal of achieving national reunification through peaceful means, and using non-peaceful means to stop Taiwan´s secession from China by the "Taiwan independence" secessionist forces.
Top legislator Wu Bangguo hailed the unanimous vote, saying it showed the "common will and strong resolve" of the entire Chinese people.
Wu said it was important for China´s efforts to maintain peace and stability in the Taiwan Straits, and to safeguard its sovereignty and territorial integrity as well as the fundamental interests of the Chinese nation.
Beijing has said the law is by no means a "bill on the use of force against Taiwan" or a so-called "war mobilization order."
Chinese authorities have repeated they would only use "non-peaceful means" to stop Taiwan´s secession should all efforts for a peaceful reunification failed, Wang Zhaoguo, vice-chairman of the NPC Standing Committee, told parliament last week.
The Taiwan issue has around since China´s civil war of the late 1940´s.