The invention pertains to the field of medical technology and provides 
triterpenoid saponin in camellia seeds, and a preparation method and medical application thereof. The 
triterpenoid saponin is shown in a general formula (1), wherein, R1 is 
hydrogen or oxhydryl or acyloxy; R2 is the 
hydrogen or the acyloxy; R3 is the 
hydrogen or the acyloxy; R4 is the hydrogen or the acyloxy; R5 is methyl or methylol or 
aldehyde group or carboxyl or metheyl carboxyl; R6 is the hydrogen or orglycosyl; the preparation method comprises the following steps: macroporous resins are degreased, extracted by 
ethanol, decocted in water, desugared and decolored to obtain crude total saponins and then go though an opened ODS 
chromatographic column and repeated 
HPLC method to obtain the total saponins of camellia seeds and 
monomer theasaponin. The 
triterpenoid saponin compounds in the camellia seeds have the functions of protecting 
gastric mucosa, being antineoplastic, reducing 
blood sugar and blood fat and thelike and are used for preparing medicaments or health-care foods having the functions of protecting 
gastric mucosa, being antineoplastic and reducing 
blood sugar and blood fat.