Abstract: Correlative studies of the Cambrian and Ordovician global boundary stratotype section and point (GSSP)-western Newfoundland Green Point section with the former GSSP candidate for the Cambrian and Ordovician boundary, Xiaoyangqiao section in Dayangcha, Baishan (formerly Hunjiang), Jilin, China indicate that the conodont species Iapetognathus fluctivagus is not present in the specified boundary layer and point at Green Point section (i.e. Bed 23),and it is a disputed species both in distribution and taxonomy. The most of the conodont and graptolite specimens as well as carbon and oxygen isotopic data submitted in the original proposal, unfortunately, are not from the "Golden Spike" section. This is totally incompatible with the principles and requirement for selecting GSSP and necessary for reassessment. The Xiaoyangqiao Cambrian-Ordovician boundary section is easy accessibility and well-exposed along beautiful rivulet. The Cambrian-Ordovician boundary interval is comprised of unmetamorphic deep water black, grey and green shale intercalated with thin-bedded gray nodular limestone, bearing complete and well represented conodont and graptolite succession from uppermost Cambrian to lowest Ordovician. In 34 m interval, 5 conodont biozones can be recognized in ascending order: the Cambrostodus, Codylodus proavus, C. intermedius, C. lindstromi and C. angulatus and in turn three graptolite-bearing beds, referred to 2 graptolite biozones, the Rhabdinopora parabola biozone with R. “praeparabola” and the Anisograptus matanensis biozone from the upper C. intermedius to C. angulatus conodont biozones. There are also a plenty of trilobite coexisting with ostracoda fossils. Combining high-resolution carbon and oxygen isotope studies the present authors suggest that the Cambrian-Ordovician boundary would be better to be defined by the first appearance (FAD) of widespread conodont C. intermedius, instead of the FAD of the controversial and rare Iapetognathus fluctivagus as boundary biomarker for the base of the Ordovician System. This boundary proposed, however, is close-if not identical-to the level specified at the GSSP section and easily recognized and correlated anywhere in the world. The maximum carbon isotopic excursion recorded above the boundary layer and appearance of the earliest planktonic graptolites—R. parabola (including R. “praeparabola”, can be make as an auxiliary signs for determination of the boundary.