Abstract: Phalaenopsis zhejiangensis seeds were used as materials to explore the effect of colchicine treatment on the chromosome doubling, and was studied by immersion method to explore the suitable conditions for obtaining polyploidy, in order to obtain suitable conditions for inducing polyploidy.The results showed that the survival rate reached 6.41%,and tetraploid, and chimera rates induction were 27.75% and 34.84%,respectively, when the seeds were cultured in liquid medium for 5 days, and then 0.20% colchicine treatment for 1 day.Compared with diploid plants, the morphological and stomatal characteristics of tetraploid plants changed significantly.The plant was stronger, the root system was developed and robust, and the plant grew faster.The number of stomata per unit area decreased, but the length and width of stomata increased by 25.19% and 26.19%,respectively.In this study, suitable conditions for colchicine to induce chromosome doubling were obtained by soaking Phalaenopsis zhejiangensis seeds.Tetraploid plants and chimera plants were obtained, which laid the foundation for the efficient introduction of excellent genes from Phalaenopsis zhejiangensis into cultivated varieties.