This thesis studied location based queries on social networks. By exploiting spatial and social data, social networks can offer many interesting services such as in public health, disaster management, tourism, marketing etc. Social relationships play a vital role in our daily lives to enable us in making right decisions in various activities and events and thus impose some influence on us. Thus, this thesis studied spatial-aware queries on social networks to recommend points of interest (POI) to the query user based on spatial and social relevance.