Demands for social interaction are higher in late childhood as individuals experience increase independence. Age-related differences in the processing of social and non-sociallypleasant emotional stimuli may imply the process of individual socialization. For example, children may regulate, express, and even experience emotions differently in different stages of development. It reflects the priority of affective processing by turning from the self-oriented rewards to the complex social and interpersonal interactions. It is essential to individuals’ psychological functioning and reflects the tendency to emotionally response to stimuli combined with the ability to modify that response. Investigating age differences in the physiological components of emotional processing (e.g., scalp-recorded event related potentials, ERPs) has important significance in terms of understanding the emotional development. Examining age-related differences in the biomarkers for emotional processing has the potential to provide an important supplement to behavioral measures. In this study, we examined age-related differences in the event-related brain potential (ERP) modulations during processing of socially and non-sociallypleasant stimuli. EEG was recorded from 19(M=20.7) adults and 17 children(M=10.12) by using the Picture Perception Paradigm. As the early components, the P2 was the prominent frontal component occurring just prior N2 around 200ms. It seems to express arousal and emotive reaction to emotional stimulus. As another important early component relevant to emotional processing, the N2 was the largest negative deflection with a medial-frontocentral topography between 200–300ms following stimulus onset. The N2 may be sensitive to the processing of emotional information. As a late component, late positive potential (LPP) is a typically sensitive biomarker of emotional processing. It reflects facilitated attention to emotional stimuli and the recruitment of prefrontal cortical resources associated with effective cognitive control. As the typical biomarkers of emotional processing, age-related differences in the early ERP components (e.g., P2 and N2) and later ERP components (e.g., LPP) were examined. Results showed that (1) as the index of the visual perception in the early processing stage, the P2 was larger for socially pleasant pictures than neutral pictures. It was large for adults than children. (2) As an index of the facilitated processing of motivationally salient stimuli, N2 was larger for children than adults.N2 was larger for socially pleasant pictures than non-socially pleasant pictures among adults. However, there was no significant difference among children.(3) As the index of emotion regulation in the late processing stage, the LPP was larger for children than adults in all time windows. In the later time window, the LPP was smaller for social than nonsocial pictures among children but had no significant difference among adults. Age-related differences in P2 and N2 in the present study again demonstrated that developmental difference is deep-rooted in the early stage of perceptual and attentional processing. As same as the findings of early ERP components, the larger LPP among children suggests that children might have higher attentioanl processing and reactivity to emotional stimulus and recruited more cortical resources during later stage of emotional processing. These results indicated that socially pleasant emotions properly had a higher priority in affective processing during development. From late childhood to early adulthood, individuals undergo age dependent changes in processing different pleasant stimuli.