Dynamic　response　of　cell　voltage　to　partially　relieving　of　current　load　of　a　fully　passive　direct　methanol　fuel　cell　has　been　studied　experimentally.　The　experimental　results　show　that　when　square　wave,　front　right-angled,　rear　right-angled　and　isosceles　triangular　wave　of　current　densities　are　loaded/relieved,　output　voltage　of　fuel　cells　is　different,　but　it　becomes　to　be　close　in　high　current　density　region.　Cell　voltage　with　methanol　concentration　of　1　mol/L　is　higher　than　that　with　methanol　molarity　of　3　mol/L　when　the　current　is　partially　relieving.　The　analysis　and　discussions　of　mass　transfer　coupling　with　electrochemical　reactions　inside　passive　fuel　cell　have　been　conducted　to　explain　the　experimental　results.