Electrospinning is highlighted in biomaterials field. The structures of nanofibers depend on various parameters, which are related closely to the bioactivity of biomaterials. The aim of this research is to analyze the structure of fish collagen nanofibers and to propose the new criterion for cell growth. This paper focused on the flow rate of solvent during the electrospinning. Through the cell culture, the relationship of the structure and cell growth is investigated. The results obtained in this study provide an understanding of the behaviors of cell growth under different structure of fish collagen nanofibers scaffold.