Abstract: To study the relation between molecular structure and storage potential of pear fruit, the 'Pingguoli' and 'Niitaka' species that have different storage potential, were used as materials for comparing the size change in pear soluble pectin and hemicellulose during storage stage using Ultrogel AcA 22 gel filtration profile method. The results showed that the hemicellulose size of 'Pingguoli' significantly bigger than that of 'Niitaka'. The soluble pectin molecular size in 'Pingguoli' not was significantly different in during storage stage, but the molecular size of hemicellulose significantly changed smaller. Instead, the soluble pectin molecular size of 'Niitaka' significantly changed smaller, at the same time without changes in the molecular size of hemicellulose. So the pears storage potentail was related to the changes of molecular structure of soluble pectin and molecular size of hemicellulose, without direct relation to the molecular structure of hemicellulose.

Key words: Pear, Storage, Soluble pectin, Hemicellulose, Molecular size