Intro: Rangeland condition assessment that is used to facilitate decision making in management of range resource has been under discussion for the last decade. Ecologists in various parts of the world have questioned the validity of earlier method of assessing range condition particularly the Ciementsian model based on plant succession and climax (Friedel, 1991, Laurenroth & Laycock, 1989). New thoughts are provoked on the way of this discussion and new ideas and approaches are emerging. The necessity of new ecological models was realized keeping in view the limitations of the successional model in meeting the management objectives of a particular range resource in a given set of ecological conditions. The paper reviews the major approaches of three ecological models and discusses their validity and application in varying sets of ecological conditions.