Ardisia silvestris Pit. is a medicinal species of significant pharmacological value that is currently facing severe population decline and is categorized as Vulnerable (VU) in the Vietnam Red Data Book (2007). Although vegetative propagation via stem cuttings has been established, the lack of standardized quantitative parameters regarding cutting types and treatment regimes has hindered its large-scale application. This study aims to establish an optimized propagation protocol in the Western Nghe An Biosphere Reserve by evaluating the synergistic effects of stem cutting position, Roots 90 concentration, and treatment duration. Experimental results identified the biologically optimal protocol using semi-hardwood (middle) cuttings treated with Roots 10 mL L⁻¹ for 2.5 hours, yielding sprouting and rooting rates of 95% and 89%, respectively. Crucially, the study also validated the high regenerative viability of the entire stem length. These findings provide a robust technical framework for securing seedling sources and facilitate the expansion of cultivation models under the forest canopy, effectively aligning biodiversity conservation with sustainable livelihoods.