Data mining as a high-tech subject is increasingly popular than before. Some data mining methods、data mining algorithms and application in social networks is introduced here. Especially, some specific social networks datasets are used to analyze the characters of social networks, the datasets are analyzed from aspects of link proportion、adjacency、out-degree、 in-degree、similarity、clustering、distance、density、transitivity、groups and reachability. Some innovative data mining knowledge of social networks can be drawn by analyzing a crowd of data sets.