To investigate the clinical effect and surface electromyography (sEMG) of rehabilitation exercise therapy in combination with total glucosides form Shaoyao Gancao decoction in treating spasticity after apoplectic hemiparalysis. Composite spasticity scale (CSS), Fugl-Meyer assessment (FMA) and modified Barthel index were compared between the exercise only group and the combined therapy group before and 1 month after the treatment to scale muscular tension, function and activities of daily living. Meanwhile, integrate EMG and root mean square (RMS) were used to detect the tension of upper limbs (biceps brachii) and ankles (tibialis anterior muscle and gastrocnemius) after the 1-month treatment. In the combined therapy group, the Ashworth and CSS scales were significantly improved compared to before the treatment (P < 0.05) and compared to the patients in the control group (P < 0.05). After the 1-month treatment, the combined therapy group showed significantly higher FMA and BI scores (P < 0.05) compared to the control group. For the combined therapy group, the sEMG was significantly improved at 1 month after the treatment (P < 0.05), while the control group only showed relatively slight improvement in the RMS of the tibialis anterior muscle and the gastrocnemius. The total glucosides form Shaoyao Gancao decoction could significantly improve the efficacy of the rehabilitation exercise therapy in the treatment of spasticity after apoplectic hemiparalysis, and its mechanism might involve the decrease of muscular tension.