It is a matter of great concern to learn about the report that the Early Cambrian small shelly fossils extend for around two thousand kilometres along the northern margin of North China Platform, and the erection of the so-called "Qinghezhen Fauna". However, recent studies show "fossils" of the "Qinghezhen Fauna" were found within high-grade metamorphic rocks, supermylonitized rocks and even igneous rocks of Archaean, Proterozoic and Late Palaeozoic. The writer has carried out a synthetical study on these "fossils" by observing every feature concerned with the relationship between "fossils" and the parent rock, and so on. The result shows that the bodies are not true fossils, but chemical precipitations formed during the acid treatment of the rock samples. Great confusions have been caused to geological mapping by using these "fossils" as criteria for age determination of strata.