Abstract: The flower bud differentiation and development of 4 varieties of Phalaenopsis had been studied on different treat time at an elevation of 700 meters. The period from treat day to flower bud differentiation is changed by different varieties. The length of florescences of 4 varieties elongated very rapidly in 30 to 80 days after treating, and reached 10cm within 40 to 63 days, there were difference between varieties and treat time. It is necessary to choice treat time according to varieties.