Spasticity is the most troublesome problems in the management in cerebral palsy. The purpose of this study was to observe the effect of FES to spasticity. 8 cerebral palsy children were selected for this study. Assessment was carried out before treatment for obtain baseline measurement of spasticity and reassessment were carried out at after 10th., 20th. treatment sessions and 24hours after treatment. The results of this study were as following that MAS scores were significantly reduced after 10th and 20th after treatment compared with pre-treatment. MAS scores were significantly reduced after 20th compared with pre-treatment. These results indicated that FES appears to reduce significantly MAS scores and maintained 24hours after treatment compared with pre-treatment.