Abstract: The purpose of this study was to reveal the morphological characteristics and developmental regularity of various components in the mature follicle wall layer of goose, and to provide a new perspective for the grading of dynamic development of mature follicles in poultry. The 5 healthy female geese from maternal line of Tianfu geese in high-yielding period were selected, and their mature follicles at each stage (diameter 0-2, 2-4, 4-6, 6-8, 8-10 mm and F5-F1) were fixed. At least 3 follicles were randomly selected in each stage during 0-10 mm, and more than 3 different regions were randomly selected for HE slicing in each follicle (except 0-2 mm stage); While more than 3 different regions were randomly selected for HE slicing in each follicle during F5-F1 stage. More than 3 areas were randomly selected from each slice for image acquisition, and 3 areas were randomly selected from each image to measure. We counted and analyzed the thickness of follicular wall, granulosa layer, theca layer and connective layer, and observed and compared their morphological characteristics. The results showed that:1) There was no complete internal theca layer in some follicles less than 2 mm in diameter. 2) There was no significant difference in follicle size and follicular wall morphology between 2-10 mm and F5 follicles. 3) In stage F4-F2 follicles, the granulosa layer cells were flat, while the thickness of theca and connective layer increased significantly (P<0.05), and the morphology of follicular wall layer changed greatly. 4) The granulosa layer of F1 follicle became loose cubes, and the thickness of each component of follicular wall changed significantly (P<0.05). These results indicate that the development process of goose mature follicle can be divided into 5 stages:0-2 mm, 2-10 mm, F5, F4-F2 and F1. These follicles at different stages have unique morphological and structural characteristics, which may be closely related to their functional differences.