Abstract: In order to understand the dynamic deformation characteristics of organic matter-disseminated sand （OMDS）， in the study， a series of dynamic triaxial tests under different natural moisture content， vibration amplitude， consolidation ratio and cyclic waveform conditions， were performed to analyze the dynamic deformation characteristics of OMDS of Hainan. The effects of natural moisture content， vibration amplitude， consolidation ratio， and different cyclic waveforms on the deformation characteristics of OMDS are analyzed from the dynamic strain-vibration frequency curve and the softening index-vibration frequency curve. The results showed that the dynamic strain of OMDS increases with the increase of the vibration amplitude and natural moisture content， however， the dynamic strain of OMDS decreases with the increase of the consolidation ratio， and increases firstly and then stabilizes while the number of vibrations increases. The softening index of OMDS decreases rapidly with the increase of the number of vibrations. Among the different waveforms， the square wave has the most obvious influence on the softening index.