of _Ganoderma_ while MycoBank lists 529 records [18]. Approximately 80 species of _Ganoderma_ are recorded in Chinese Fungi [24], of which _G. lucidum_ and _G. sinense_ are described as medically beneficial macroftungi in Chinese medicine [25]. However, other species, such as _G. capense_, _G. cochlear_ and _G. tsugae_ also play an important role in traditional folk medicine. In addition, pharmacological studies have also used the extract and chemical constituents of other _Ganoderma_ species [22; 26; 27; 28; 29; 30].  
The chemical constituents and the biological activities of 25 species of _Ganoderma_, namely _G. amboinense_, _G. annulare_, _G. applanatum_ (synonym _G. lipsense_), _G. australe_, _G. boninense_, _G. apense_, _G. amrosum_, _G. casaurinicola_, _G. cochlear_, _G. colossus_, _G. concinnum_, _G. ellipsoideum_, _G. fornicatum_, _G. hainanense_, _G. lucidum_, _G. mastoporum_, _G. neo-japonicum_, _G. orbiforme_, _G. pfeifferi_, _G. resinacum_, _G. sinense_, _G. thaecola_ (as _thaecolum_), _G. tropicum_, _G. tsugae_ and _G. weberianum_ were studied and reported in this review. Several chemical constituents such as ganoderic acids, lucidenic acids, 12-hydroxyganoderic acid, ganorbiformin, lucidimines [31] and other compounds have been reported from various _Ganoderma_ species during recent decades [29; 32; 33; 34; 35].  
Triterpenes, polysaccharides and peptidoglycans are one of the major types of bioactive substances [36; 37] responsible for the various biological activities of several species in _Ganoderma_ (e.g., _Ganoderma lucidum_). Triterpenoids and ganoderic acids that play a critical role in pharmacological activities are also present in _G. applanatum_ and _G. orbiforme_[33; 36; 38; 39; 40; 41; 42]. Besides _G. applanatum_[43; 44], _G. colossus_[45] and _G. pfeifferi_[46], _G. resinacum_[45] have also been identified as potential _Ganoderma_ natural antioxidants.  
_G. anbonitense_[47], _G. annulare_[48], _G. applanatum_[49; 50; 51], _G. bonitense_[52], _G. calidophilum_[53], _G. capense_[54], _G. carnosum_[55], _G. cochlear_[56; 57; 58], _G. colossum_[59], _G. concinnum_, _G. neo-japonicum_[60], _G. fornicatum_[61], _G. hainanense_[62], _G. leucocontextum_[63], _G. lucidum_[64; 65; 66; 67], _G. mastoporum_[68], _G. mbrekobenum_[69], _G. resinacum_[70], _G. sinense_[71; 72; 73], _G. thaecola_ (as _theacolum_) [74], _G. tropicum_[75], _G. tsugae_[76], _G. weberianum_[77] were reported to contain bioactive compounds of great interest.  
The members of the genus _Ganoderma_ are rich in novel \"mycochemicals\", including polysaccharides [78], steroids, fatty acids, phenolic compounds, vitamins, amino acids and triterpenoids [69; 79; 80; 81]. _Ganoderma_ polysaccharides are a hot topic in the medicinal mushroom research field [82; 83; 84; 85; 86; 87; 88]. Although polysaccharides are found to be one of the main bioactive constituents, their high molecular weight and complex structure limit their use in the drug market [85]. The _Ganoderma_ polysaccharides are well known for their diverse bioactivities such as antitumor, immunomodulatory, anti-hypertensive, antidyslipidemic and hepatotoxicity activities. _Ganoderma_ polysaccharides have been developed into medicines, dietary supplements, healthy foods, treat and prevent diseases, and are continuing to serve as important leads in modern drug discovery [86; 87; 88].  
Previous reviews were mainly focused on the anticancer properties [89; 81; 90; 91; 92; 93; 94; 95; 96], hep-atoprotective activities [97], antimicrobial activities [42] and mechanisms of _Ganoderma_ triterpenpenoids [35; 98; 99; 100].  
Herein, we review the structures, bioactivities, and biosynthesis pathways of the small molecular constituents of triterpenoids from 25 species of _Ganoderma_ to lay a foundation for further research on the development of new medicines.