Abstract: To identify microbial resources and provide a theoretical basis for high-yielding Agastache rugosa crops, an endophytic bacteria, HX-2, was isolated from healthy leaves of A. rugosa and identified through morphological observation and 16S rDNA sequence analysis. Indole acetic acid production, phosphate solubilization, salt and copper tolerance, and the effects on seed germination and seedling growth of A. rugosa were assessed in vitro and in vivo. The isolated bacterium was identified as Bacillus megaterium which is able to produce indole acetic acid and dissolve inorganic phosphorus. It was tolerant of pH’s ranging from 5.0 to 9.0, 0.5% to 8% NaCl and 0 to 6 mmol·L^-1 Cu²⁺. After inoculation with HX-2, seed germination energy, seed germination percentage, seedling height, root length, leaf area, seedling fresh and dry weights, chlorophyll content, root vigor and stem diameter of A. rugosa improved by 22.6%, 18.0%, 17.1%, 18.2%, 14.7%, 22.8%, 25.0%, 10.0%, 19.2% and 10.4%, respectively (P<0.05). These results suggest that HX-2 is a growth promoting bacteria which can be developed as a microbial fertilizer for agricultural production.