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During the last decades,several integrated studies of Tethyan Jurassic/Cretaceous boundary sections from different countries were published with the objective to indicate problems for the selec tion of biological,chemical or physical markers suitable for identification of the Jurassic/Cretaceous boundary - the only system boundary within the Phanerozoic still not fixed by GSSP.Drawing the boundary between the Jurassic and Cretaceous systems is a matter of global scale discussions.The problem of proposing possible J/K boundary stratotypes results from lack of a global index fossils,global sea level drop,paleogeographic changes causing development of isolated facies areas,as well as from the effect of Late Cimmerian Orogeny.This contribution summarizes and comments data on J/K boundary interval obtained from several important Tethyan sections and shows still existing prob lems and discrepancies in its determination.