The Mesoproterozoic Wumishan Formation in the Jixian section ofTianjin is a succession of 3300-m-thick carbonate strata formed in a period of about 100 Ma (1310 ± 20 Ma-1207 ± 10 Ma). In this succession of strata, the carbonate metre-scale cyclic sequences belonging to peritidal type with an approximately symmetrical lithofacies succession are best developed. The wide development of 1:4 stacking patts shows that these metre-scale cyclic se quences are genetically related to the short-eccentricity cycles, which are called the Wumishan cyclothems that could truly represent sedimentary cycles. Generally, massive and thick-bedded calcareous dolomites and dolomitic limestones of stromatolite biostromes and thrombolite bioherms constitute the central part of the Wumishan cyclothems. The lower and upper parts consist of tidal flat dolostones, sandy-muddy dolostone and the top part is composed of lagoonal facies dolo mitic shales with a paleosol cap. Therefore, an approximately symmetrical lithofacies-succession is formed. Many features such as the clear deepening and shoaling vectors of cyclothems, and all kinds of marks of fresh-water diagenesis indicate that the Wumishan cyclothems are the product of autocyclic sedimentation goved by allocyclic high-frequency sea level changes. The results of a Markov chain analysis reaffirm the existence of the lithofacies-succession model of the Wumishan cyclothems. The boundaries of the Wumishan cyclothems are marked by the instantaneous exposed punctuated surface, which leads to the discrepancy between the cyclothems and the parasequences of the sequence stratigraphy ter minology system. It is difficult to form a judgment that the time span of the Milankovitch cycles in the Precambrian is certainly equal to that of the Phanerozoic, but the regularly vertical stacking patts of the seventh-order rhythms, sixth order cyclothems and fifth-order parasequence sets still indicate their consistency with the duration of the Milankovitch cycles in the Phanerozoic.