Chronic early life stress (ELS) influences neuronal development and significantly increases the lifetime risk for the development of cognitive and affective pathology. It has been suggested that disruption in early life care impaired cognitive abilities in adulthood and affected neuronal development in the hippocampus in rodent models. However, the influences of ELS in emotional behaviors and hippocampal development in adolescence remain unknown. To clear these points, we examined the effects of ELS by housing mouse dam with limited nesting and bedding material from postnatal days 2-9 (P2-P9) and examined behaviors in 30 days (P30) of offspring. We also investigated hippocampal differentiation and microglia activation. Adolescent (P30) ELS mice showed over-response of stress escape in forced swim test. By immunohistochemical analysis, dentate gyrus of the hippocampus in ELS mice showed a significant increase in cell proliferation and survival. Furthermore, the number of IBA1 positive cells in the hilus was increased in stressed mice. Collectively, our findings demonstrate that chronic ELS affects adolescent behaviors and hippocampal development. It is necessary to investigate the relationship between these behaviors and hippocampal development in order to clarify the stress response in early childhood.