Objective To explore the effect of four-type seeds powder with salt for hot-ironing on San-yin meridian of the hand on the spasticity of the hemiparetic upper limb after stroke. Methods A total of 108 patients with poststroke upper limb spasticity in the convalescent stage were randomized into two groups, with 54 in each group.The control group received conventional treatment, nursing and rehabilitation training, while their counterparts in the intervention group additionally received four-type seeds powder with salt for hot-ironing on San-yin meridian of the hand. The effects were evaluated after 4 weeks of intervention. Results Forty-nine patients in the control group and 48 in the intervention group completed the study.The intervention group reported better improvement in spasticity, upper limb motor function and clinical outcomes compared with the control group after the intervention （P＜0.05,P＜0.01）.None of the participants developed changes in vital signs and regional injury. Conclusion Four-type seeds powder with salt for hot-ironing on San-yin meridian of the hand could effectively ameliorate poststroke upper limb spasticity, improve upper limb motor function and clinical outcomes.