Abstract: This research is concerned with optimization of Mg²⁺ , Ca²⁺, Fe²⁺, Mn²⁺ and Zn²⁺ for protocorm-like body proliferation in liquid culture of Dendrobium huoshanense by one factor-atatime and orthogo nalmatrixmethods. Results showed that, except for Zn²⁺, the effects of othermetal ions on PLB proliferation were significant and the order was Fe²⁺ >Mn²⁺ >Mg²⁺ > Ca²⁺ > Zn²⁺ . The optimal concentration combination for PLB proliferation was determined as 1.5 mmol·L ^-1 Mg²⁺ , 4.5 mmol·L ^-1 Ca²⁺ , 0.1 mmol·L ^-1
Fe²⁺, 0.5 mmol·L ^-1 Mn²⁺ and 0.06 mmol·L ^-1 Zn²⁺. Proliferated PLBs remained the potential of plant regeneration. The amount of regenerated plantlets from pergram PLBs through proliferation in optimized liquid medium was 1 985.2 and was about 4.2 times that from PLBs that proliferated on origina lmedium.