The emergence of User Generated Content (UGC) and social media, enables common users to have great influence on other users adoption and decision making behavior. In current research, perceived information usefulness is always taken as the only antecedent of UGC adoption, which is not enough to explain the underlying mechanism, especially in new social media context. This study proposes a new theoretical model with new social factors. Different dimensions of tie strength are innovatively applied in the model to analyse the new context characterized by weak ties.