Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) is a precious and economic medical herbal of Vietnam. In recent years, with micro-propagation and conservation of this herb tendency, plant regeneration is a necessary problem in this research about somatic embryogenesis play an important role. Therefore, this study was conducted for estimating affection of explant sources, mineral component of culture media, type, plant growth regulators, spermidine (polyamine groups), proline (amino acid groups) and carbohydrate sources on somatic embryogenesis of Ngoc Linh ginseng. With three explant sources such as leaf, petiole and main root, leaf explants having 0.5 x 0.5 cm size were cultured on Murashige and Skoog (MS) medium supplemented with 1.0 mg.rl 2,4-dichlorophenoxyacetic acid (2,4-D), 0.2 mg.rl kinetin and 0.5 mg.rl naphthaleneacetic acid (NAA) to establish embryogenic culture. The effects of exogenous spermidine and proline on enhancement of somatic embryogenesis were investigated. The results showed that spermidine (0.1 mM) and proline (300 mg.rl) resulted in a high frequency of somatic embryogenesis (93.3 percent and 86.7 percent, respectively). To further optimize a culture medium for induction of embryo formation of P. vietnamensis, three carbohydrate sources (sucrose, glucose and fructose) from 10 to 60 g.r1 were tested. Among them, glucose and fructose were not suitable for somatic embryogenesis in this species while sucrose at 50 g.r1 produced the highest embryogenic frequency (86.7 percent) and number of embryos per responding explant (167). This study confirmed the importance of spermidine, proline and osmotic potential provided by sucrose in enhancement of somatic embryogenesis.