Abstract: During the long-term natural evolution, the scales of teleost fish become ultra-thin and lightweight and have a good flexibility as well. In order to reveal the structure and mechanism of scales, two scales of fish (cyprinus carpio, carassius auratus) from New Zealand were studied in this paper. Firstly, the surface morphology, cross-section and hierarchical structure of two fish scales were investigated. Then, uniaxial tensile tests were conducted. The results show that the surface morphologies of two scales are various from different location of scales, while two scales are both consist of outer hard bony layer and inner soft collagen layer. For cyprinus carpio scales, through a quasi-linear region from the stress-strain curves, the stress of samples softens slightly before reaching the first peak stress, after which the stress drops to zero. While the stress of carassius auratus scales increases through a quastic-linear region, and then reaches the peak, lastly drops to zero gradually. Comparing the mechanical parameters between cyprinus carpio scales and carassius auratus scales, it's suggested that the tensile strength of carassius auratus scales is superior to that of cyprinus carpio scales. However, the ductility of cyprinus carpio scales has a prior ductility than the carassius auratus scales.