Early life stress has been long-lasting effects on an individual stress response, behavior, and emotion throughout life, which increased a risk for psychiatric disorders. Early life adverse experience should be one of the serious causes of eating disorders such as anorexia nervosa and bulimia nervosa. Maternal separation (MS) is widely used as a laboratory model of early life stress. In the present study, we used the conditioned place preference (CPP) test to evaluate preference for chocolate, with the aim of determining whether MS affects the reward and motivation for palatable foods. Mice were separated from their dam daily for 3h from postnatal day (PND) 1 to14. Following MS procedure, mice were kept with their dam in home cage until weaning at PND21, and then mice performed the CPP test to evaluate chocolate (as a palatable food) preferences at 9-week-old. The CPP test analysis indicates that control mice showed a significant preference for chocolate-associated compartment, but MS mice did not. These results suggest that MS mice declined reward and motivation for palatable foods and/or impaired in the memory of place where mice obtained palatable foods. Furthermore, we found that female mice experienced MS tend to lose body weight and food consumption from the pubertal stage. A low nutrient status following the early life stress is one of the risk factors for causing reproductive dysfunctions. Then, we assessed reproductive development and function (vaginal opening, estrus cycle), and examined the expression of kisspeptin and gonadotropin-releasing hormone (GnRH) that are involved in the neuronal regulation for reproduction. Our findings show that early life stress may contribute to abnormal feeding behaviors and reproductive dysfunction.