Abstract: In order to clarify the effect of collagen fiber size and its concentration on the performance of fish skin collagen fiber-starch composite films,fish skin was pretreated by acetate(3,6,9,12 h)to obtain different types of collagen fibers(CF3,CF6,CF9,CF12)with different sizes. The properties of the blend films added with different types and amount of collagen fibers were investigated. Composite films were characterized by Fourier transform infrared spectroscopy,differential scanning calorimetry and scanning electron microscopy. The results showed that the elongation at break and WVP of the composite films increased and the solubility decreased after adding collagen fibers. The tensile strength increased with CF3 7.5% or CF6 10%. The composite films prepared by 10% CF6 had excellent tensile strength. When adding CF9 and CF12,the tensile strength of the composite film decreased. The composite film and pure starch film prepared by adding 10% CF6 were characterized. The results showed that collagen fibers had good compatibility with starch. Collagen fibers were interlaced in the starch film,and the hydrogen bond was formed between the collagen fibers and the starch granules. However,the thermal stability of the composite film was decreasd.