Abstract: In order to explore the physiological and molecular mechanisms of leaf color change in red maple, three color types of leaves with significant differences at different developmental stages were used as experimental materials and biochemical and transcriptome sequencing analysis were carried out to clarify and analyze physiological characteristics and differential genes related to leaf color changes. The results showed that the chlorophyll content, chlorophyll synthesis precursor ALA and PBG content, and carotenoid content significantly increased and anthocyanin content, total phenol and flavonoid content significantly decreased. Transcriptome analysis showed that there were 6 931 differentially expressed genes in red maple leaves at different developmental stages. The structural genes CHS, ANS, CHI, HHT, F3′H, FLS, and ART, which were key enzymes in the anthocyanin biosynthesis pathway, were highly expressed in the red leaves. Two gens of MYB transcription factors（MYB2 and MYB113） and two gens of protein kinases（TMK1 and RUL1） were highly expressed in the red leaves. The study preliminarily elucidated the physiological characteristics of leaf color differences and identified structural and regulatory genes related to anthocyanin synthesis pathways in red maple at different developmental stages, which will provide rich genetic information for further research on the molecular mechanisms of leaf color changes in red maple.