The objective of this study is determining and analysing the effect of regional expansion, infrastructure development and productive economic activities toward people welfare in South Sorong. It is also conducted in order to know and analyze the dominant program on the people welfare in South Sorong. This research was conducted in South Sorong with quantitative and qualitative data applying multiple regression analysis. Regression analysis result showed that there is a significant relationship on variable regional expansion with people welfare in South Sorong-Papua. The development of infrastructure has a significant influence on people welfare in South Sorong-Papua. Productive economic activities also have an influence on people welfare in South Sorong-Papua. Partial analysis testing result discovers that infrastructure development factor has dominant effects on people welfare compared to the factors of regional expansion program and productive economic business.