Abstract: Objective： A self-assembled small peptide RADARADARADARADA （RADA16-1）can form a long fiber hydrogel，which has the function of surgical hemostasis，to explore the long fiber assemble dynamics and hemostasis mechanism of peptide RADA16-1. Methods： Through circular dichroism spectrum，atomic force characterization and rheological mechanics analysis，kinetics of long fiber self-assemble had been studied. Hemostatic models of spinal cord injury and liver trauma were established to study the effect of blooding control. Results：The results of circular dichroism spectrum indicated that RADA16-1 in solution was beta folding characteristics both before and after ultrasound. The results of atomic force characterization and rheological mechanics analysis showed that RADA16-1 can self-assemble into long fiber which length was about（786. 34 ± 96. 54）nm，and the long fiber assembled process of RADA16-1 was positively associated with time after ultrasound. Meanwhile，a negative correlation was detected between the long fiber length and the bleeding time in animal models. Conclusion：The small peptide RADA16-1 solution can rapidly situ hydrogelize to long fiber form，can be used in surgery as hemostatic.