A domain-adapted portable machine translation device for closed captions using dynamic translation resources and a method thereof are provided. The device and method improve translation performance with respect to various specialized domains by automatically recognizing style and domain of a caption sentence, dynamically constructing specialized translation module and knowledge, and performing automatic translation with optimal translation resources suitable for a corresponding sentence. Not only does the domain-adapted portable machine translation device for closed captions exhibit improved translation performance for sentences in various domains, but it can also be freely linked with various media devices through input/output terminals.