There were all sorts of different events which may arouse our emotional experiences in daily life. When processing and perceiving these emotional stimuli, there may include different emotional reactivity. They could be influenced by biological factors as well as cultural factors. It had been recognized that emotions exist along a social/nonsocial emotional dimension. The sociality dimension may reflect the differences between basic biological drives (nonsocial) and complex social interaction (social). Even though previous studies examined the important differences in social and non-social emotional stimuli, most of them focused on the negative emotions. However, as an important and indispensable part of the field of emotion study, it is necessary to include the study of positive emotions. Positive emotions are considered to be adaptive experiences and helpful to promote individual's psychological well-being. In current study, we aimed to examine the differences of the emotional reactivity when processing social/nonsocial positive emotions. Emotion perception is a process that integrates physiological, cognitive, and behavioral components. A series of even-related brain potential (ERP) studies is reviewed demonstrating the consistent and robust modulation of specific ERP components by emotional images. Specifically, emotional compared to neural pictures elicit an increase in the early ERP components (e.g., P1, P2, and N2) and the late positive potential (LPP). Modulations of the ERP components are thought to reflect the facilitated processing of, and increased attention to, motivationally salient stimuli. Therefore, ERPs provide a powerful measurement tool for capturing neural activity related to emotional responding. In the present ERP study, we used the Picture Perception Paradigm to explore the differences in brain cortical reactivity to social/nonsocial positive emotions. When 20 undergraduates watched and evaluated these social, neutral, and nonsocial pictures, their ERPs were recorded. 180 pictures were used in the study. Results showed that (1) the P1was larger for emotional than neutral pictures. As for P2, the difference was not significant, (2) the N2 was larger for social than nonsocial pictures; but had no significant differences between emotional and neutral pictures, (3) as for LPP, we divided into three time windows: the first one was from 300ms to 600ms, the second one was from 600ms to 1000ms, and the last one was from 1000ms to 1500ms. At the early time window, there were no significant results among different stimuli. At the second and the third time windows, the LPP was larger for social than nonsocial pictures. However, there was no significant difference between emotional and neutral pictures. The results suggested that positive social emotions properly had a higher priority during the emotional processing. And the advantage could be reflected in subjective experiences and physiological responses. These findings deepened our understandings of social/nonsocial emotions. Besides, these results could also provide empirical supports to processing of positive emotions. The future research could make significant progress in laying out the foundations identifying the diverse mechanism of emotional processing of different emotional stimuli.