A voice recognition apparatus includes a voice recognizer configured to recognize user utterance, a storage unit configured to store a plurality of tokens, a token network generator configured to generate a plurality of recognition tokens from the recognized user utterance, search for a similar token similar to each of the recognition tokens and a peripheral token having a history used with the recognition token among the plurality of tokens stored in the storage unit, and generate a token network using the recognition token, the similar token, and the peripheral token, and a processor configured to control the token network generator to generate the token network in response to the user utterance being recognized through the voice recognizer, calculate a transition probability between the tokens constituting the token network, and generate text data for corrected user utterance using the calculated transition probability.