Motion　artifact　removal　is　one　of　the　most　important　issues　in　portable　ECG　(electrocardiogram)　monitoring.　Motion　artifacts　are　usually　accompanied　by　significant　baseline　drift.　Adaptive　filtering　has　been　used　to　filter　motion　artifacts　and　baseline　drift.　The　3-axis　acceleration　signal　is　selected　as　the　noise　reference　signal.　Results　show　that　motion　artifacts　and　baseline　drift　have　been　removed　in　filtered　ECG,　and　the　QRS　complex　of　the　filtered　ECG　has　clearly　appeared.