Abstract: 【Objective】 This study aims to analyze the phenotypic differences of wool density in Chinese Merino and screen candidate genes related to wool density traits in Chinese Merino in the hope of providing reference for elucidating the molecular regulation mechanism of wool density in the sheep. 【Methods】 The wool density and hair follicle density of Chinese Merino sheep were measured and statistically analyzed by biostatistical methods. Meanwhile, the skin of Chinese Merino sheep with different wool densities was selected for transcriptome sequencing to identify candidate genes related to wool density traits. 【Results】 The average wool density of Chinese Merino high wool density group ( HWD group ) was (9,852.02±1,673.98) roots / cm², which was significantly higher than that of low wool density group ( LWD group ) (5,390.61±1,365.67) roots / cm² ( P < 0.01 ). There was no significant difference in the average primary hair follicle density between the HWD group and the LWD group. The average secondary hair follicle density, the ratio of primary hair follicle density to secondary hair follicle density, and the average total hair follicle density in the HWD group were significantly higher than those in the LWD group (P < 0.01 ). Using the skin transcriptome data of Chinese Merino sheep with different wool densities, a total of 521 differential genes were screened out in the HWD group compared with the LWD group, of which 280 were up-regulated and 241 were down-regulated. Through the analysis of differential gene enrichment, differential gene interaction and differential gene expression verification between high and low density groups, KRT18, KRT16, KRT86, KRT38, LOC101116157, CCN3, SPARC, C7, ATP12A, ANGPT4, WNT16, S100A1 and S100A4 differentially expressed genes were screened, which affected the growth and density of Chinese Merino wool. 【Conclusion】 There are differences in gene expression profiles of skin tissues of fine wool sheep with different wool densities. The different expression of these genes may affect wool density by changing the process of skin hair follicles and wool growth.