This study aims at analyzing thermal Performance of the mixed water-brick walls as a thermal storage wall for Passive building to promote energy conservation and to maintain indoor comfort level by thermal design of buildings. The experiments were carried out by constructing a container (3m × 6m × 2.4m) with water and brick walls facing to the south. The computer simulation programs were used to analyze the thermal performance of the model for long-term base. The results show that the water wall performs well for high stable temperature variation and the brick wall works as an effective means of the thermal radiator for maintaining a better indoor condition.