This study was designed to investigate the effects of inquiry chemical experiment in chemistry teaching in promoting preservice teachers’ critical thinking skills. A pretest and posttest experimental design with a comparison group was employed to validate the effectiveness of the proposed approach. Ten chemical experiments were selected, and 42 chemical preservice teachers aged at 19-22 voluntarily participated in the research. The California Critical Thinking Skills Test (CCTST) was used to assess the level of preservice teachers’ critical thinking skills. The CCTST pre and post scores of the preservice teachers in chemical inquiry experiments training have significant differences, which show that the inquiry chemical experiment has certain promoter action to the preservice teachers’ critical thinking skills. The findings indicated that the implementation of inquiry chemical experiment improved critical thinking skills of the preservice teachers significantly.