Real-time　dynamic　substructuring　(RTDS)　is　an　experimental　technique　that　splits　the　structure　under　test　into　coupled　parts　that　run　in　parallel.　The　structural　component　exhibiting　unpredictable　behaviour　is　tested　in　the　laboratory　while　the　remainder　of　the　structure　is　modelled　numerically.　As　the　test　proceeds,　the　dynamic　force　state　at　the　physical-numerical　interface　is　measured　and　a　transfer　system,　usually　a　servo-hydraulic　actuator　or　shaking　table,　is　used　to　impose　the　commensurate　response　on　the　physical　substructure.　The　integral　dynamics　of　servo-hydraulic　transfer　systems　can　frustrate　RTDS　implementation　by　destabilising　the　system.　Many　have　noted　the　deleterious　stability　implications　of　excessive　phase　lag　in　terms　of　a　pure　time-delay.　However,　because　of　the　existence　of　magnitude　variations　and　more　complex　phase　characteristics,　pure　time-delay　is　too　simple　to　represent　the　inherent　nature　of　servo-hydraulic　transfer　systems.　This　paper　considers　RTDS　stability　in　light　of　comprehensive　transfer　system　dynamics.　A　transfer-function　model　of　a　servo-hydraulic　transfer　system　is　adopted　and　used　to　reflect　the　oversimplification　of　pure　time-delay.　The　concept　of　gain　margin　is　employed　to　reveal　the　drawbacks　of　the　pure-delay　based　RTDS　stability　analyses.　In　order　to　overcome　the　drawbacks,　a　new　method　based　on　gain　margin　was　developed.　The　comparative　analyses　demonstrate　that　the　gain　margin　based　method　is　tailored　to　predict　the　stability　boundaries　of　a　RTDS　system　incorporating　comprehensive　transfer　system　dynamics.　The　validity　of　the　technique　is　verified　experimentally　through　virtual　and　authentic　RTDS　system　employing　a　shaking　table.　The　performance　of　delay　compensated　shaking　table　RTDS　is　also　assessed　in　perspective　of　stability.