Abstract: The Mesoproterozoic Wumishan Formation in Jixian section of Tianjin is composed of 3 300m thick carbonate strata with a duration of about 100Ma(1 310±20Ma-1 207±lOMa)．In this set of strata, particularly carbonate meter-scale cyclic sequences belonging to peritidal type with approximately symmetrical lithofacies-succession fabric are developed very wel1. The widespread development of superimposed patterns of 1:4 shows that these meter-scale cyclic sequences are genetically related to the short-eccentricity cycles, which are called figuratively Wumishan cyclothems and could represent true sedimentary cycles. Generally, massive and thick-bedded limedolostones and dolomitic limestones of stromatolite biostromes and thrombolte bioherms constitute the central part of Wumishan cyclothems, the bottom and upper part are consisted of tidal flat dolostones, the top part is composed of lagoon-facies dolomitic shales with a cap of paleosol layers. Therefore, the approximately symmetrical lithofacies-succession fabric is formed. Many features such as the clear deepening and shoaling vectors of cyelothems, and all kinds of fresh-water diagenesis marks suggest that the Wumisham cyclothems are the products of autocyclic sedimentation governed by allocyclic high-frequency sea-level changes. The results of Markov chain analysis reaffirmed the objective existence of 1ithofacies-succession fabric of Wumishan cyclothems. The boundaries of Wumaishan cyclothems are marked by instantaneous exposed punctuated surface, which lead to the discrepancy between the cyclothem and the parasequerce of sequence stratigraphy terminology system defined by Vail et al. (1977). It is difficult to judge that the time-span of Milankovitch cycles in Precambrian is certainly equal to those of the Phanerozoic, but the regularly vertical stacking patterns of seventh-order rhythms, sixth-order cyclothems and fifth-order partasequence sets stil1 indicate their consistence with the period duration of Milankovitch cycles in the Phanerozoic.