Background: Cognitive theories of depression stress a causal and maintaining role of maladaptive interpretive bias in sad mood.However,from evolutionary perspective of views,interpretive bias may also be an adaptive consequence of sad mood.It has been vastly reported that depression is associated with pessimistic cognitive bias which may be detrimental,while some recent evidence shows that cognitive bias can be beneficial in some circumstances,suggesting interpretive bias might be a coping function resulted from lowered mood.Yet there is no direct evidence whether sad mood can bias interpretation of emotional ambiguity.Method: In a between-group design,51 participants underwent sad mood induction(n=30)or control condition(n=21).Modified Ambiguous Cue Interpretation(ACI)test was used as a measure of online interpretive bias.Results: Control group showed positive interpretive bias,whereas this bias diminished in sad group.No significant interaction between group and cue ambiguity was found.Mood predicted interpretive bias in both sad group and the whole sample,and accounted for most of the variance.Conclusion: The current study provided the first experimental evidence that sad mood could affect interpretive bias in non-depressed individuals.Taken together with previous evidence,it highlights the possibility that depression-linked interpretive bias may be a response to mood alteration that deviates from normal span due to excessive sadness,which in turn may contribute to worsening the mood,resulting in a pathological vicious circle.