Abstract. Irian Jaya study aims to analyse the flexibility and productivity of the urban informal sector of regional economy in Jayapura. The approach used is qualitative in nature. The findings of the study show that the informal sector in Jayapura is very flexible in recruiting human resources of varying backgrounds (gender, age, education, even capital). The study also finds that the productivity of the sector is very high as the profit gained by the informal sector actors is significantly higher than the cost. Factors attributing to the flexibility of the informal sector in Jayapura are labour and demand whereas factors attributing to productivity are labour and demand, which are positively correlated, and flexibility, which is negatively correlated.