Sleep schedule of participants were regulated and varied across experiments, so it remains unclear if nighttime sleep and daytime nap play a different role in memory consolidation thus yielding conflicting results about the effect of sleep on consolidation of emotional memory. This study explored the interactive effect of habitual sleep duration and daytime nap on consolidation. Sixty-three young adults (Mean age = 20.38, SD = 1.39, 63.5%male) were randomly assigned to either the Nap or the Wake group with no significant group differences in age, sex, body mass index, habitual sleep duration and sleep quality. Average baseline sleep duration (SLEEP) was calculated from sleep diaries completed five days before the lab day. Participants were instructed to rate the valence of eyes stimuli adopted from ¡¥¡¥Reading the Mind in the Eyes test. The Nap group then obtained a 90-min polysomnograph-monitored sleep opportunity, when the Wake group remained awake. An incidental recognition test of the stimuli was administered after the Nap/Wake period. Memory discriminability of stimuli of positive, neutral and negative valence, was compared using two-way analysis of variance with CONDITION (Nap&Wake) and SLEEP (<5 h, 5–6.5 h, >6.5–8 h & >8 h) as between-subject factors. For neutral memory, there were significant main effect of CONDITION with the Nap group performing better (p = .009) and main effect of SLEEP (p = .003) with worse performance in those with <5 h sleep. There was significant CONDITION*SLEEP interaction, p = .016. Post-hoc tests indicated that the nap group performed better in the <5 h sleep group (p < .05) but not in the other three groups (ps > .05). For negative memory, a significant main effect of CONDITION was found with better performance in the Nap group (p = .004). No main effect of SLEEP but significant CONDITION*SLEEP interaction was found (p=.045). Post-hoc tests indicated that better performance in the Nap group was found among those with <5 h, 5–6.5 h and >6.5–8 h sleep (ps < .05), but not those with >8 h sleep (ps > .05). For positive memory, no main or interaction effects were found. Our results showed that a nap strengthened memory of neutral valence in only the most sleep-restricted group, but the napping effects on memory of negative valence were present in groups of all sleep duration, except for the most sleep-satiated. This study provided the first evidence on the interaction between habitual sleep duration and a daytime nap on emotional memory. This work was supported by HKU Seed Funding Program for Basic Research.