Abstract: On the basis of the features of high frequency cyclic deposition types and relevant studies,the authors put forward their opinions about the 3rd to 5th order cycles and their corresponding sequence division.According to their suggestion,each order contains two suborders.The 5th order is marked by the minor cycle and composite minor cycle or the essential sequence and composite essential sequence;the 4th order is represented by the minor cycle bundle and minor cycle group or the essential sequence bundle and essential sequence group;the 3rd order cycle is the transgressive regressive cycle and composite transgressive regressive cycle or the transgressive regressive sequence and composite transgressive regressive sequence.The average ages of the minor（meter scale）cycle and cycle group of littoral tidal flat carbonate rocks of the transgressive regressive sequences 2 at Daguizhoutan are 33.3 ka and 400 ka,respectively,which are close to the slope period 34 ka and the long escentricity period 413 ka of the earth orbit prior to the Quaternary,respectively.So it is inferred that the origin of Early Triassic littoral tidal flat high frequency cycles at Daguizhoutan is probably related to that.