<p id="C2">In December 2019, an outbreak of a novel coronavirus disease (COVID-19) occurred in Wuhan, Hubei province, China. COVID-19 is characterised by fever and severe acute respiratory symptoms in early stages, which can rapidly progress to acute respiratory distress syndrome that is associated with high mortality. As of 9 February 2020, 40171 cases have been confirmed cumulatively and 23589 suspected cases were collected in China. The wide and rapid spread of COVID-19 has intensely captured public attention, leading to increased mental health stress. Timely mental health care and intervention during the outbreak of COVID-19 is urgently needed not only for confirmed or suspected patients and frontline medical workers, but also for the general public.<br/>Previous studies showed that affirmation of personal values can buffer psychological stress responses in various threat situations. The goal of the present study was to investigate whether an intervention involving reflection on personal values was capable of buffering psychological stress responses during the outbreak. We recruited 220 participants who completed a questionnaire on their personal values. Those in the self-affirmation group were asked to choose and write their thoughts and feelings of a personal value that made them feel important to themselves while those in the control condition were asked to do the same for a personal value that they thought was important to others. Both groups completed a Self-rating Anxiety Scale (SAS) and Beck Depression Inventory (BDI) prior to and 7 days after intervention. <br/>We used two-way repeated measures analysis of variance (ANOVA) to evaluate the buffer effect of value affirmation on stress responses with time of assessment as a within-subjects factor and intervention group as a between-subjects factor for anxiety and depression. Our results revealed a significant relationship between time and intervention for the reduction of anxiety. Further simple effect analysis demonstrated that the control group showed heightened levels of anxiety 7 days after intervention compared with before, whereas participants who affirmed their values did not show any increase. This effect remained significant after controlling for sex, age, educational level, and annual family income. However, no significant differences were found for depression. <br/>The present study demonstrates for the first time that an experimental intervention involving the affirmation of personal values can buffer psychological stress response during the COVID-19 epidemic. Specifically, participants who affirmed their values did not show increased levels of anxiety compared with control participants. Self-affirmation is easy to accomplish since it does not require professional guidance or a distinct environment and occupies little time, it would be a convenient strategy for the public to cope with psychological stress during the outbreak.