Abstract： The investigation of the cognitive and emotional characteristic of resilient individuals has significant implications for understanding the development and mechanisms of resilience. As a new perspective on emotion functioning, emotional complexity has important implications for physical and psychological health. Nevertheless, the relationship between emotional complexity and resilience has been rarely investigated especially in Chinese cultural settings. In this study, we aimed to explore the differences in daily positive and negative emotion states, emotional complexity, and emotion regulation strategies between three groups of college students with high-, intermediate-, and low-resilience levels. With a sample of 252 participants from six universities in Shanghai, we firstly conducted screening and grouping processes according to two vital standards of resilience, i.e., severity of stress/adversity that they faced and positive outcome of psychosocial adaptation that they developed. Thereafter, we carried out a 15-day follow-up study using the Experience-Sampling Method (ESM) to investigate grouped participants’ daily emotional states and their emotional complexity. Furthermore, we administered a questionnaire to investigate the participants’ emotion regulation strategies. The statistical software SPSS 19.0 was adopted to conduct the paired sample t-test and the analysis of variance (ANOVA) to analyze the data. Results indicated that the most frequently experienced daily emotions in the participants were active, energetic, nervous, and trembling with fear. Additionally, antecedent-focused regulation was used more frequently to regulate negative emotions (t (99) = 18.06, p < 0.001), and mainly for down-regulation (t (99) = 9.55, p < 0.001). Up-regulation strategies were used more frequently in positive emotion regulation (t (99) = 3.96, p < 0.001). There were significant differences in daily emotional states between high-, intermediate-, and low-resilient participants Specifically, the high-resilient group experienced positive emotions more frequently and more intensively (F (2,97) = 7.50, p < 0.01; F (2,97) = 6.22, p < 0.01). An index of positive emotional experience was computed by subtracting negative emotions from positive ones, showing that high-resilient participants had more positive emotional experiences than those with low resilience. Participants with high resilience reported the highest positive emotional granularity scores among the three groups (F (2, 97) = 4.26, p < 0.05). A similar discrepancy was not found in negative emotional granularity, emotional range and mixed emotions. There were also differences in emotion regulation strategies between different resilient groups. High-resilient individuals released and expressed positive emotions more frequently (F (2, 97) = 3.55, p < 0.05), and rarely use suppression strategies (F (2, 97) = 3.69, p < 0.05). In contrast, the low-resilient individuals was more likely to use cognitive up-regulation strategies to regulate negative emotions (F (2, 97) = 6.41, p < 0.01). In conclusion, positive emotion is the building block of resilience, and the awareness, differentiation and regulation of positive emotion has significant implications for adaptation, growth and thriving. Different types of emotion regulation strategies have differential impacts on physical and mental health. It is implied that a guided exercise on emotion regulation and emotion awareness will promote individual resilience.