This research discusses the design approaches of new buildings constructed in historic districts. The new interventions in those places may threat their distinguished characters if they were not carefully designed. Therefore, design within these sensitive contexts reuqires special criteria to ensure the protection of their visual consistency and urban advantages. The research aims at indicating the suitable design strategies for these places through both theoretical and analytical approaches. The theoretical approach tries to conclude the main principles of designing in those areas by studying the international charters related to this issue and the different opinions of urban theorists and researchers about it, as well as discussing the guidelines of some historic districts in America and Europe to derive the mutual concepts and basic standards of building in such districts. The analytical approach depends on these results to analyze selected projects built within various historic contexts and adopting different design approaches. A comparative analysis is performed to deduce a classification of the design strategies suitable for historic contexts as well as the guidelines and appropriate uses of each strategy.