Provided is a user command processing method and system to provide and adjust an operation of a device by analyzing a presentation of a user speech. The user command processing method includes managing at least one pre-defined operation to be performed according to a user command, a plurality of options being preset in relation to each of the at least one pre-defined operation, receiving a user command at least including a voice input received from a user, selecting an operation corresponding to a keyword extracted from the voice input, determining at least one option corresponding to the extracted keyword among a plurality of options preset in relation to the selected operation, according to a presentation of the voice input, and performing the selected operation in association with the determined at least one option.