The 21st century continues to use technological advances that change of communication, socialization, and private versus public information. Adolescence is the part of life that succeeds from childhood, the period of existence preceding maturity or age; the whole early part of life, from childhood to manhood. Social networking is a phenomenon which has existed since society began. Constant online communication affects children, making it difficult for them to communicate and concentrate when they are away from the screen. The present study aimed to assess the addiction of social networking which affect the mental health. The study was carried out in a selected college of Chennai. Total 30 sample were included for data collection. A question was prepared comprises of 10 question covering the main objectives of the study. Finding concluded that the impact of addiction of social networking on adolescence affecting the mental health shows the result of Severe impact 8(27%), Moderate impact 10 ( 33%), Mild impact 12 ( 40%) is existing.