A dialog processing system may include a communication device configured to receive information sent from the outside and circumstantial information; a storage configured to store a rule and a dialog template related the rule; a rule determiner configured to compare a condition of the rule and the information to generate a determined rule; a situation determiner configured to determine to express the determined rule based on the determined rule and circumstantial information collected from the outside; and a result processor configured to generate text to be expressed based on the determined rule and the dialog template and output the text according to a signal sent from the situation determiner.