Abstract:Changes of alcohol-insoluble solids （AIS）, water-soluble pectic substances （WSP）, acid- and alkalisoluble pectic substances （HP, OHP） were determined during banana （Musa acuminata cv. Brazil） fruit softening. Results showed that the contents of AIS decreased continuously with the fruit ripening, and declined rapidly at climacteric stage. The contents of water-soluble pectic substances （WSP） were found increased, while those of acid- and alkali-soluble pectic substances （HP, OHP） decreased. Such changes were little at the beginning of fruit storage, but became more obvious when firmness declined rapidly. It was shown that changes of cell wall substances played an important role in banana fruit softening.