Abstract: 【Objective】 'Sha 01' is a bud mutation of 'Korla fragrant pear'. Its fruit has excellent quality, but low fruit firmness that it is not benefit to storage and transportation, which affects the popularization and application of this variety. In this study, the difference of firmness between the two varieties was analyzed from the point of view of fruit tissue structure. 【Method】 The paraffin section method was used to observe the cuticle, epidermal cells, tannin cells, parenchyma cells, sclereids group and parenchyma cells around sclereids group of the two pear varieties in maturation phase. 【Result】 The cuticle thickness of the Sha 01 and Korla fragrant pear were 5.44 μm and 9.44 μm. The number of epidermal cells and tannin cells layers in Sha 01 was less than Korla fragrant pear, most of them in Sha 01 were slender, and the aspect ratio was 0.60 and 0.35, however, most of the epidermal cells and tannin cells in Korla fragrant pear were short and thick. The sclereid group diameter of the Sha 01 and Korla fragrant pear were 287.16 μm and 362.04 μm, and the parenchyma cells length around sclereid group of the Sha 01 and Korla fragrant pear were 343.06 μm and 262.71 μm. There was a very significantly positively correlation between the fruit firmness with pericarp and the thickness of cuticle. The fruit firmness without pericarp was very significantly positively correlated with tannin cells aspect ratio, diameters of sclereid group and length-width ratio of parenchyma cells, and was very significantly negatively correlated with tannin cells diameter and parenchyma cells length around sclereid group, there was a significant negative correlation between the fruit firmness without pericarp and width of parenchyma cells.【Conclusion】 It was shown that there are differences in the pericarp and pulp tissue structure between Korla fragrant pear and Sha 01. The thickness of the cuticle and the number of epidermal cell layers in the pericarp, the number of tanninl cell layers and shape of the tannin cells, the shape and size of the parenchyma cells and the diameter of sclereids group in the pulp are the main factors affecting the difference in fruit firmness between the two varieties.