Protestors assembled in the city during a forum on defense industries of the United States and Taiwan, holding banners and boards that read, "We want peace, not war," "No more debts for arms sales," "No Taiwan independence," and other slogans.
The groups accused US arms groups of siphoning money from the island's budget and sabotaging the peaceful development across the Strait, according to a joint statement issued by the groups.
The statement said huge military spending has become a burden for Taiwan, and the United States has been using the island to hinder the development of the mainland.
Continuous military purchases will not save, and will only destroy, the future of the island, said the statement.
Protesting groups included the Labor Party of Taiwan, the Alliance for the Reunification of China, and the China Tide Association.