A method for manufacturing antibacterial polyester master batches and fibers containing nano-silver particles, the method includes the acts of: mixing a reducing agent, glycol and a silver precursor together to compose a first mixture; esterifying terephthalic acid and glycol to compose a second mixture containing block polymers; mixing the first and second mixtures to make the block polymers further polymerize to achieve a polyester liquid containing nano-silver particles; optionally, cooling the polyester liquid to solidify; and selectively, granulating the solidified polyester to obtain a polyester master batches or melting spinning the polyester to obtain polyester fibers. By reducing the silver ions during polymerizing reaction, the reduced silver particles are separated by polymerized polyester molecules so that the silver particles are evenly distributed inside the polyester master batches without coagulation.