Abstract: 【Objective】The aim of the study was to clone the octamer-binding transcription factor 1, to investigate whether over-expression of Oct-1 regulated the major genes of coat color in melanocytes of mouse at the transcriptional levels and to explore its influence on the formation of melanin. 【Method】 The CDS region in Oct-1 gene were cloned from melanocytes of mouse by primers and PCR to build a mouse Oct-1 cloning vector and eukaryotic expression vector. The KEGG PATHWAY, NCBI, and Transfec softwares were adopted to analyze the biological information of the obtained sequence. Over-expression of Oct-1 was conducted in the melanocytes of the 5^th generation mouse through the cell transfection technique and transfer efficiency was observed by fluorescence microscope. The content of melanin in melanocytes was detected by spectrophotometer. The level of major genes were detected using real-time PCR and the proteins of MITF，TYR，TYRP-1 and TYRP-2 were detected using western blot.【Result】Results showed that the 2 313 bp cDNA sequence of Oct-1 gene was obtained by sequencing and splicing. Eukaryotic expression vector was successfully constructed with specific TYRP-2 gene promoter of mouse and a startup report gene of green fluorescent protein. KEGG PATHWAY analysis obtained 34 candidate genes related with coat color，and the promoters of these 34 candidate genes were found by NCBI. The major gene of coat color regulated by Oct 1 was determined by using Transfec software. Under the fluorescence microscope, green fluorescence could be identified in melanocytes of mouse. The contents of melanin in melanocytes were reduced (P＜0.05). Real-time PCR results showed that Oct-1 mRNA was significantly increased (P＜0.001),witch indicated Oct-1 high transfection efficiency. MITF mRNA was significantly reduced to 0.70 times (P＜0.01) and TCF mRNA was significantly reduced to 0.66 times (P＜0.01). The expressions of Ras, Frizzled, ERK2 and TYRP-2 mRNA did not change. TYR mRNA was significantly increased to 7.69 times (P＜0.01), TYRP-1 mRNA was significantly increased to 3.11 times (P＜0.01), αMSH mRNA was significantly increased to 18.49 times (P＜0.001), AC mRNA was significantly increased to 6.88 times (P＜0.01), c-kit mRNA was significantly increased to 18.75 times (P＜0.001), ET1 mRNA was increased to 1.50 times (P＜0.05), ETB-R mRNA was significantly increased to 13.47 times (P＜0.001), and CAM mRNA was increased to 1.46 times (P＜0.05). Western blot results showed that MITF protein was significantly reduced to 0.67 times (P＜0.01), TYR protein was increased to 1.16 times (P＜0.05), TYRP-1 protein was increased to 1.15 times (P＜0.05) and TYRP-2 protein did not  change.【Conclusion】The 2 313 bp length CDS region of mouse Oct-1 gene was got by PCR, TA cloning and nucleic acid sequencing technology. Major gene of coat color regulated by Oct 1 was determined by bioinformatics analysis. Results of the study suggested that after over-expression of Oct-1, the expression of MITF and TCF was reduced, while that of TYR, TYRP-1, αMSH, AC, c-kit, ET1, ETB-R and CAM was increased. Therefore, the Oct-1 may mediate the alteration of coat color through regulating genes involved in the formation process of coat color.