This paper discusses Social Development Approach (SDA) to poverty reduction programs and social welfare. Some objective and subjective (cultural) processes, at the late decades of 21th century, have challenged the prevalent patterns of poverty reduction and social welfare, which has led to the proposal of social development or community-based development approach. This new approach is different from traditional welfare approach, in terms of its indexes, aims, concentrations, methods, measures and agents. The first section of this paper deals with historical and conceptual background of SDA and the second section proposes the concept of "community-based poverty reduction and social welfare". This concept extends SDA to local levels specially at urban areas. The third section of this article traces the SDA approach in the fourth development plan and The last section of the paper sums up proposed arguments and insights, and emphasizes the necessity of implementing SDA in to welfare and poverty reduction activities and plans in the country