Retrieval can not only assess what was learned in a prior episode but also strengthen memory retention. Episodic context account posited that the act of thinking back to an original study episode (i.e. being in a retrieval mode) is the mechanism of retrieval practice effect. However, whether the retrieval practice effect could be influenced by emotional arousal is still unclear. We aim to investigate the role of retrieval mode and emotional arousal on retrieval practice effect by using event-related potentials. Using negative and neutral items, participants were asked to either restudy or perform a source memory test, and then a final source memory test was conducted. The behavioral results revealed that memory of neutral and negative items similarly benefited from the retrieval practice condition. Consistently, event-related potential results revealed that retrieval mode effect was found for both the neutral and negative items. These findings suggested that emotion arousal might not influence testing effect when source memory test was applied for the retrieval practice condition, and retrieval mode plays an important role in these effects.