The researchers used the study to identify the effect of using the internet in leisure time on the social isolation of students in the preparatory stage in Dakahlia Governorate. The researchers used the descriptive approach. The internet usage scale was applied in leisure time and the social isolation measure was designed by the researchers to collect the data. The study was conducted on a sample of (873) students in the preparatory phase in Dakahlia governorate for the basic sample and (50) for the survey sample. The most important results were the awareness and awareness of the students to use the Internet in leisure time. The social networking sites (Facebook, Twitter, Watts App) Internet use in most students, there is a positive impact of the dimensions of the use of the Internet in leisure time on the social isolation of students