Abstract: A pot experiment was carried out to study the effects of Mo application on growth, biomass, nutrient contents in different parts and total saponin content in rhizome of paris polyphylla var.yunnanenis. There were four levels of Mo application: 0, 0.2, 0.4 and 0.8 mg/kg. The results show that the plant height, photosynthesis rate, biomass and rhizome are increased significantly with the application of Mo, the highest values are 0.4, 0.2, 0.4 and 0.2 Mo mg/kg respectively. There is an increasing tendency of N contents in leaves and new rhizome under the medium and low levels of Mo (0.2, 0.4mg/kg）compared with no Mo treatment (control), while the N contents in leaves and new rhizome are significantly decreased under the high level of Mo (0.8mg/kg).The P contents in leaves and new rhizome are decreased under the Mo applications, while the P contents in stems are increased. The K contents in leaves are increased under the Mo applications, while the K contents in stems are decreased. The Mo contents in leaves, stems, and new rhizome of the Mo application treatments are significantly higher than those of the control, and the tendency is increased at first and then decreased. The total saponin contents in new rhizome of the Mo application treatments are significantly increased compared with control, the highest of which is the Mo 0.8 mg/kg treatment. Comprehensively considering the growth status, increased weight and saponin content of rhizome, Mo contents in different parts, the suitable level of Mo application is between 0.2 and 0.4 mg/kg for paris polyphylla var.yunnanenis in this experiment.