A model to analyze argumentation in Early Childhood Mathematics Education is presented, called Argumentative Situation (AS), to characterize argumentation in Childhood mathematics classroom. From an integrative approach that considers contextual and functional aspects of argumentation, AS considers five components: argument (what is argued? and why?); interaction (who argues?); functions of argumentation (what is it argued for?); character of the argument (how is it argued?); and Mathematics (what is argued about?). We present analyses of three class episodes in order to exemplify the use of AS and to account for its scope and limitations. We finish by discussing projections of the model.