<p>Previous studies demonstrated that Mindfulness based Cognitive Therapy (MBCT) is effective for reducing rumination. However, little is known about the effectiveness of mindfulness on the process of getting worse of rumination. The present study conducted cross-sectional and 6 months longitudinal studies to replicate a previous finding that mindfulness traits buffer the influence of causal analytic rumination on uncontrollability of rumination. However, there was no evidence that mindfulness traits prevent the development of rumination. Additional analysis showed Nonreact aspects of mindfulness predicted low uncontrollability of rumination 6 months later. These results suggest that mindfulness contributes to inhibit cognitive reactivity before occurring of rumination rather than prevents worsening of rumination which already occur. We discussed the importance of subdivided examination of mindfulness and directed future studies.</p>