Electronics not only change the pattern of our life style, but also have an inevitable influence on the development of children as they are being used more and more often among children at very young age. Children and adolescents use electronics as the tools to learn, entertain, communicate and present. Many researches have paid attention to the impact of electronics use on child development. Cultivation theory, displacement theory, use-and-gratification theory, and ecological systems theory have been employed to interpret the impact of electronics use on child development. These theories try to interpret how electronics influence children’s cognition, emotion and the way they practice in society from different perspectives. In order to examine the effect of electronic media, we need to adopt more comprehensive theories. Ecological system theory emphasizes that children develop from the reciprocal transitions between the child and the broader environmental contexts in which a child is situated or operates. The ecological techno-subsystem, a dimension of the microsystem of ecological systems includes child interaction with both living (e.g. peers) and non-living (e.g. hardware) element of communication, information, and recreation technologies in immediate or direct environments. Empirical evidences have shown that the impact of media on children depends on three distinct but interrelated factors: attributes of the child; characteristics of the electronic media stimuli; and the varied environmental contexts surrounding the child’s media use. One central finding of studies to date is that the content delivered by electronic media is far more influential than the media themselves. Most studies find a small negative link between the total hours a child spends viewing TV and that child’s academic achievement. But when researchers take into account characteristics of the child, such as IQ or socioeconomic status, this link typically disappears. Content appears to be crucial. Viewing educational TV is linked positively with academic achievement; viewing entertainment TV is linked negatively with achievement. When it comes to particular cognitive skills, researchers have found that electronic media, particularly video games, can enhance visual spatial skills. Media exposure affects children’s social development. Children can learn about the nature and causes of different emotions from watching the emotional experiences of media characters and that they often experience empathy with those characters. Strong evidence shows that violent television programming contributes to children’s aggressive behavior. And a growing body of work indicates that playing violent video games can have the same harmful effect. Children’s susceptibility to media influence can vary according to their gender, their age, how realistic they perceive the media to be, and how much they identify with characters and people on the screen. Researches indicate that online communication is beneficial to children and adolescents，researchers propose rich-get-richer and social-compensation hypotheses to explain the different effect of online communication. Reaearchers may enrich our understanding the relationship between electronics use and children's development from research technique and content in future. Reaearchers should develop measurement approaches appropriate for capturing children’s media use in the digital age, the most effective approach will be to triangulate measurement techniques.Others could focuse on identifying the patterns of brain activation when children watching TV ,playing video games and so on , identifying whether using electronics in very early years could change the structure of the brain or change the patterns of brain activation with cognitive neuroscience perspective and techniques.