Several studies had been reported regarding the effects of plant growth regulators on callus growth of different plant species (Nadia and Li, 2011). When using different concentrations in single auxin treatment, the addition of 2.4-D increased the growth in the rhizome callus of R. coreanum with the maximum at 0.2 mg/l of 2.4-D, but increasing the levels of 2.4-D suppressed the callus growth (Table 2). A combination of cytokinin BAP at 0.2 mg/l with the best auxin treatment (0.2 mg/l 2.4-D), produced profuse amounts of whitish and friable callus (Table 2). When kinetin was used instead, the amount of biomass recorded lowered than that of the best BAP (0.2 mg/l) (Table 2).