For early initiation of spontaneous breathing trail and to improve the effectiveness of weaning from ventilator, all ventilator-dependent patients should be assessed for weaning readiness prior to weaning. However, the concept of weaning readiness has been unexplored in literature. According to Walker and Avant (1995), the focus that underpins concept analysis is to develop an operational definition of weaning readiness, including continual assessment and multidimensional assessment. Through a list of defining attributes, and model case development, these will clarify the basic concepts in order to reduce confusion in communication among clinical staff. Also guild to formulate the assessment tool of weaning readiness.