Optimization of the protocorm-like body (PLB) formation of Phalaenopsis and Dendrobium hybrids was performed by determining the effects of plant growth regulators (PGRs) and different parts and division sizes of the PLB. For both genera, the base part was the best for the proliferation of PLBs, yielding the highest number of PLBs on a PGR-free medium for Phalaenopsis and medium containing $0.1{mu}M$ NAA and $10.0{mu}M$ BAP for Dendrobium. As regards the division size, four-division sections resulted in a higher PLB formation efficiency for Phalaenopsis, while two-division sections produced a higher PLB formation efficiency for Dendrobium. It is expected that these findings will be applicable to efficient PLB formation of other Phalaenopsis and Dendrobium orchids.