The present invention relates to a technique of automatically spacing sentence, to a sentence spacing systems and methods that can be applied to particular computing power is automatically recognized by the spacing portion of the input sentence from a low portable terminal equipment. Comprising the present invention generates a probability value information set the probability value by the qualities from the correct answer corpus To this end, a learning process consisting of the value of probability information with generating an error correction rule from the real applying results, and the user inputs and a sentence service (the user input sentence) sentence spacing method and system to apply a set of rules, wherein the error correction information and the probability values ​​in order to include the application and outputting the user input sentence is corrected to the spacing. Thus, the computing power to implement effectively lighter sentence automatic spacing system and method operating a wireless terminal, etc. dripping compared to a typical PC, such as a mobile phone or PDA Spacing, n-gram, CRFs, corpus, a mobile terminal, a probability model