Low well-being is common among Chinese pregnant women but few effective interventions currently exist to improve prenatal stress and negative emotions. Mindfulness-based stress reduction (MBSR) has been proved to be effective in reducing stress and rarely studies were focused on Chinese pregnant women. The aim of the current paper is to investigate the effects of 8-week MBSR on prenatal stress, anxiety and depression among Chinese pregnant women. A sample of 66 pregnant women randomly allocated into either the MBSR group (n=34) or the control group (n=32). Participants in the MBSR group received a group 8-week, 90-min each time intervention. The results found a significant interaction between time and condition for prenatal stress (F=45.51, p<0.001, η 2=0.427), anxiety (F=19.30, p<0.001, η 2=0.240), while depression showed no time-by-group interaction (F=0.29, p=0.589, η 2=0.005). As for the sub-scale of state anxiety, while there was only no time effect (F=3.68, p=0.060, η 2=0.057). The findings of this study preliminary indicated effects of the MBSR intervention on self-reported prenatal stress and anxiety in comparison to a treatment-as-usual control. Effect on depression was not observed may due to the low level of depression of participants. This study provides preliminary evidence that MBSR is suitable for Chinese pregnant women and be effective in decreasing prenatal stress, anxiety.