[Purpose] The purpose of this study was to investigate the relationship of knee proprioception with muscle strength and spasticity in stroke patients. [Subjects and Methods] The subjects were 31 stroke patients. The subjects received an explanation of the procedures and methods and provided informed consent before the experiment. A measurement board was used to determine the the proprioception deficit of the knee as a proprioception test. The proprioception test consisted of a passive and active angle reproduction test. A manual muscle test and modified Ashworth scale were used to evaluate knee muscle strength and spasticity level. The data were analyzed using an independent t-test and Spearman correlation. [Results] The results of this study revealed a significant difference between the affected side and non-affected side in the passive angle reproduction test and a significant difference in the correlation of the proprioception level with muscle strength and spasticity level. [Conclusion] This study indicates that the knee proprioception level is associated with spasticity and muscle strength in stroke patients.