This paper provides a method for microscale fiber spinning and the in situ construction of a 3D fibrous scaffold on a single microfluidic platform. This platform was also used to fabricate a variety of fibrous scaffolds with diverse compositions without the use of complicated devices. We explored the potential utility of the fibrous scaffolds for tissue engineering applications by constructing a fibrous scaffold encapsulating primary hepatocytes. The cells in scaffold were cultured over seven days and maintained higher viability comparing with 3D alginate non-fibrous block. The main advantage of this platform is that the fibrous structure used to form a scaffold can be generated without damaging the mechanically weak alginate fibers or encapsulated cells because all procedures are performed in a single platform without the intervention of the operator. In addition, the proposed fibrous scaffold permitted high diffusion capability of molecules, which enabled better viability of encapsulated cells than non-fibrous scaffold even in massive cell culture.