Abstract: ASR is a specific hydrophilic protein family in plant, playing important role in plant growth and development, ripening and senescence and abiotic stress. And mASR3 gene is a kind of transcription factors found in plant in recent years. In order to further study its function, the synthesized gene mASR3 was cloned into over-expression vector (pMD1), formed a recombinant plasmid called pMD1-mASR3. The recombinant plasmid was transformed into Arabidopsis thaliana through Agrobacterium tumefaciens. The cotyledon was green, hypocotyls was longer and the taproot was longer in the transformed Arabidopsis. The transgenic plants laid the foundation for its further study of function.