Nationalism is an important element that Indonesian people need to have. This needs to be fostered from teenagers as a future cadre of the nation. Nationalism is formed by six dimensions, namely love of the country, desire to participate in nation building, desire to pursue achievements, desire to use science and technology, desire to uphold the law and desire to enter international competitions. The level of adolescent's nationalism is influenced by family factors such as gender, parental education, parental work, parental marital status and communication time with parents. This study is a case study conducted at SMA X, Tambun Selatan. Samples were taken by stratified sampling and cluster sampling. The purpose of this study is to determine which dimension provides the most important role to the level of nationalism and the profile of students who have high level of the found nationalism dimensions based on the family factors. The data analysis method used is the PLS method. From the results of the study it was found that the dimensions that provide the most important role to the level of nationalism is the love of the country. Family factors that affect the love of the country are the last education of father and mother and parents'.