This study aims to develop Critical-Inquiry-Based-Learning (CIBL) learning model to improve CT ability of preservice teachers. CIBL learning model developed by three criteria, namely the validity, practicality, and effectiveness. Validation of the model involves 4 expert validators through the mechanism of the focus group discussion (FGD). CIBL learning model declared valid to improve CT ability, with validity level (Va) of 4.20 and reliability (r) of 90,1% (very reliable). The practicality of the model was evaluated when it was implemented that involving 17 of preservice teachers. The CIBL learning model had been declared practice, its measuring from learning feasibility (LF) with very good criteria (LF-score = 4.75). The effectiveness of the model was evaluated from the improvement CT ability after the implementation of the model. CT ability are evaluated using the scoring technique adapted from Ennis-Weir Critical Thinking Essay Test. The average score of CT ability on pretest is -1.53 (uncritical criteria), whereas on posttest is 8.76 (critical criteria), with N-gain score is 0.76 (high criteria). Based on the results of this study, it can be concluded that developed CIBL learning model is feasible to improve critical thinking ability of preservice teachers.