Abstract: This paper discusses igneous petrotectonic assemblages of various tectonic settings: 1. mid–ocean ridge spreading; 2. oceanic island; 3. island arc; 4. MORS–type and SSZ–type ophiolites; 5. active coutineutal marginal arc; 6.compositional polarity of subduction–related magmatic arcs; 7. continental collision; 8. continental rift; 9. stable craton or platform, etc. It is emphasized that the tholeiitic ( TH ), calc–alkaline ( CA ) and alkaline ( A ) series defined from various parameters by different authors have different scientific meanings. In this paper it is indicated that the same written terms of TH, CA and A but with various meanings could easily result in abuse of these terms, especially for the recognition of the tectonic settings. The difference between MORS – and SSZ –type ophiolites in terms of igneous petrotectonic assemblages is discussed. The lowest MgOwt% of the HMA is suggested ( Table 2 ), based on the data of petrological experiments. The terms of magnesian andesite–dacite and adakite are discussed, and in turn, the Kay's magnesian andesite–dacite of higher Sr/Y, lower FeO/MgO, and higher MgOwt% as well as higher Ni, Cr contents, are comprehensively used, which can be more satisfactory to define the slab–melt, rather than the single parameter of high Sr/Y. The various schemes of classification for the continental collision are indicated, and it is necessary to be careful for using these schemes. The post–orogenic and the continental rifting A type granites are suggested to be associated with or without the CA/r, respectively, and the meaning of A and CA, here, is determined by the Peacock's alkali–lime index.