In　this　paper,　the　kinematics　and　dynamics　of　free-flying　dual-arm　space　robot　systems　are　analyzed.　By　use　the　method　of　multibody　dynamics,　the　dynamics　equations　and　Jacobi　relationship　of　dual-arm　space　robot　systems　are　established.　Based　on　the　results,　the　control　problem　for　dual-arm　space　robot　to　track　the　desired　trajectory　in　workspace　is　discussed.　Because　of　the　high　structure　complexity　and　the　parameter　uncertainty　of　dual-arm,　space　robot　systems,　the　scheme　of　variable　structure　control　with　better　robustness　to　uncertainty　and　disturbance　is　proposed.　The　advantages　of　the　control　scheme　proposed,　are　that　it　needn＇t　to　control　the　position　of　the　base.　To　show　the　feasibility　of　the　proposed　control　scheme.　a　simulation　study　of　dual-arm　space　robot　systems　is　presented.