Objective: To compare the efficacy on muscle recruitment and coordination ofconstraint therapy, constraint therapyplus electrical stimulation, and occupational therapy, to treat the handbysfunction. Method: Sixty-eight children with hemiplegic cerebral palsy were randomly allocated toconstraint therapy, constraint therapy plus electrical stimulation, and occupational therapy group. Three groups received two weeks of treatment. All participants were measured at baseline and two weeks, three and six months after treatment using measures of surface electromyograpby. Results: When grasping maximallyused by involved hand, root mean square of both hands, integrated electromyography and co-contraction ratioof involved hand changed significantly at each follow-up session for all children, as well as reducing in integrated electromyography of noninvolved hand after six months of treatment (P<0.05). Constraint-induced movement therapy plus electrical stimulation group showed greater rate of improvement in integrated electromyography of involved wrist extensors, and co-contraction ratio than other two groups at three and six months, as well asimproving in root mean square of involved wrist extensors than occupational therapy group (P<0.05). Whengrasping maximally used by noninvolved hand, all children changed significantly in root mean square of bothinvolved hand and wrist extensors of noninvolved hand from baseline to each follow-up session, as well asreducing in integrated electromyography of wrist extensors of involved hand after six months of treatment forconstraint-induced movement therapy plus electrical stimulation group (P<0.05). Conclusion: Constraint therapyplus electrical stimulation is likely to be best in strengthening recruitment and coordination of involved arm, andisolated movement control ability of bimanual hand in children with hemiplegic cerebral palsy.