Abstract: 【Objective】To investigate the gene expression changes at the transcriptional level and screen carotenoid biosynthesis related differentially expressed genes（DEGs）in Lycium barbarum L. fruits at different developmental stages，which could reveal the molecular mechanism of carotenoid content differences in Lycium barbarum L. fruits at different developmental periods and provide theoretical references for molecular breeding of Lycium barbarum L.【Method】 The transcriptional profiles of fruits of Lycium barbarum L. Qixin 1 at the green fruit stage（YD），colour change stage （ZD）and ripening stage（XD）were analyzed by Illumina NovaSeq 6000 high-throughput sequencing. Using |log2 Fold Change|≥1 and false discovery rate（FDR）< 0.05 as the criteria，and the combination of KEGG，GO，KOG，NR database annotation information and PubMed database literature to screen the differentially expressed genes（DEGs）related to carotenoid metabolism and synthesis. The carotenoid content of Lycium barbarum L. fruits at different developmental periods was determined. Real-time fluorescence quantitative PCR was used to verify the reliability of the transcriptome data of the 8 DEGs.【Result】The total number of DEGs in YD vs ZD group，YD vs XD group and ZD vs XD group was 6480， 1497 and 7781 respectively，of which 3946，827 and 2888 were up-regulated and 2534，670 and 4893 were downregulated respectively. There were a total of 234 DEGs in 3 fruit developmental stages. The results of GO functional annotation showed that in the YD vs ZD group，YD vs XD group and ZD vs XD group，1700，579 and 1657 DEGs were annotated to the 3 major functional categories of biological process（BP），cellular component（CC）and molecular function （MF）respectively. The KEGG signaling pathways in all the 3 comparison groups were mainly focused on the metabolic pathways and the biosynthesis of secondary metabolites. A total of 50，18 and 68 DEGs related to efficacy components were mined from the 3 comparison groups of YD vs ZD group，YD vs XD group and ZD vs XD group respectively，and 34 DEGs involved in carotenoid synthesis pathway，of which 12，5 and 17 were enriched in the YD vs ZD group，YD vs XD group and ZD vs XD group respectively. Fruits of Lycium barbarum L. Qixin 1 at all 3 developmental periods contained carotenoids，and the overall carotenoid content showed a trend of decreasing and then increasing with the development of Fruits of Lycium barbarum L. Qixin 1，with the carotenoid contents of YD，ZD and XD fruits being 0.35，0.25 and 1.20 mg/g respectively. Five carotenoid synthesis pathways key enzyme gene，namely PSY，PDS，ZDS，CHYB，ZISO and CYP97A3 had relative expression higher than 100. The high expression of key enzyme genes of carotenoid anabolism PSY，PDS，ZDS and CHYB and low expression of the carotenoid catabolism related enzyme genes ZEP and NCED were conducive to the accumulation of carotenoids. The relative expression of 8 DEGs in Qixin 1 fruits was basically in agreement with the transcriptome sequencing results were basically consistent.【Conclusion】During the green fruit period and ripening period of Fruits of Lycium barbarum L. Qixin 1，the key enzyme genes of carotenoid metabolic pathway PSY，PDS，ZDS and CHYB are expressed at high level and the expression of carotenoid catabolism related genes ZEP and NCED are decreased，these genes synergistically promote the accumulation of zeaxanthin and β-carotene in the ripening fruits of Qixin 1 Lycium barbarum L..