It is well known that arousal modulates memory. Such as, relative to neutral ones, emotional and arousing events are generally recollected with greater frequency. This is likely an adaptive function that effectively highlighting important stimuli and events to protect and prepare an organism for similar future occasions. However, painful memory also related to mental disorders in sometimes. Therefore, how to erase or reduce negative emotional memory have recently received considerable study. Given the relationship between arousal and memory, one possible way to reduce emotional memory maybe is to decrease arousal responses to emotional events. Humans have the unique ability to monitor and voluntarily regulate their emotional states. One particular form of emotion regulation, cognitive reappraisal, has been proved to be could decrease physiological and subjective arousal effectively. For example, it was observed that, in laboratory experiments, voluntary instructed reappraisal (IRE) decreases skin conductance responses successfully. In addition to IRE, the individual differences in spontaneous use of reappraisal (SRE) are also known to influence arousal response. It was found that SRE could reduce subjective arousal ratings to emotional words and inhibit the ability of arousal to induce memory enhancement. All of these researches provide a possibility that both IRE and SRE maybe could exert effects on emotional arousal and memory. Therefore, firstly, the aim of this study focuses on the modulating effects of IRE on arousal and emotional memory. Secondly, we also want to know if the modulating effects of IRE are related with the individual differences in SRE. A sample of 28 college students (11 male and 17 female) completed the Emotion Regulation Questionnaire firstly, and then viewed emotionally neutral and negative pictures while they attempted to either decrease emotion arousal elicited by the pictures by IRE or to simply watch the pictures. Concurrent changes in emotional arousal were assessed respectively with skin conductance responses (SCR) and self-report arousal ratings of participants. Picture memory was assessed with an immediate recall test and a two weeks delayed recognition test. It was found that, (1) compared with simply viewing pictures, IRE generated significant decreased self-report arousal and SCR responses; and in line with this, participants showed decreased recognition for pictures presented during the IRE condition. (2) In the watch condition, the level of SRE negatively related with SCR and recognition in for negative pictures. (3) The SCR degree was significant lower in participants with high level of SRE (HR) than in participants with low level of SRE (LR), and only LR but not HR participants showed significantly decreased SCR and recognition for pictures in the IRE condition. In conclusion, our results suggest that IRE could exert down-regulation influences on emotional arousal and subsequent memory. Meanwhile, individual differences in SRE is an important factor in affecting the modulation effects on changes of emotional arousal and memory which induced by SRE. That is, for HR individuals, the habitual use of reappraisal maybe could spontaneously reduce the arousal response to emotional events, and IRE induced no significant effect on emotion states and memory to pictures; and for LR individuals, though they showed more arousal responses to emotional pictures, IRE could significant decrease SCR, subjective arousal ratings and recognition.