Organic carbon isotopic records from lake sediment s are valuable pro xies used to indicate g lacial-interglacial change in atmospheric pCO₂, major changes in catchment vegetation, lake level fluctuations, and variations in regional temperature.While factors af fecting variations in organic carbon isotope (δ¹³C_org)are numerous, predominant control(s)on the shif t of δ¹³C_org value w ere of ten found out with the aid of evidence from o ther investigations on the lake sediment s such as paleolimnological, geochemical, sedimentological and palynological studies, as well as molecularisotopic stratig raphy.Environmental explanation models (EEMs), proposed by investig ators in the previous researches for those long-term isotopic records showing different curve patterns, are reviewed. Recognition and clarification of source materials of organic matter (OM)buried in lake sediments and of possible changes in organic source materials in the past are fundamental aspects and important for the environmental interpretations of δ¹³C_org records.OM contents, organic carbon to nitrogen (C/N)rat ios, hy drogen index (HI), petrog raphic examination of organic remains in lake sediments of ten provide useful information on organic productivity, origin, maturation, and diagenesis.Hence, they should be presented, if available, alongside w ith δ¹³C_org record.In this way, EEMs can then be properly applied, otherwise new EEMs may well be provided.In addition, identification of individual biomarkers of ten provides indication of specific terrestriall, aquatic, and bacterial sources of organic mat ter in lake sediments.New carbon iso topic signals ref lecting Glacial/interglacial environmental change may well be indicated by molecular-isotopic stratigraphy.Long-term δ¹³C_org records from many interested lakes in China aw ait us to investigate, depending largely on bottom sediment cores from those lake centers become available.These records have g reat potential for the researches of the past global changes.