Utilizing the Drop Tower Beijing/NMLC, the characteristics of two-phase gas-liquid flow and power performance of a direct methanol fuel cell (DMFC) are studied experimentally in normal and microgravity conditions. It's found that CO
2 bubbles in anode channels of DMFC move much slowly in microgravity, and that their shapes change from ellipsoid to globosity and their sizes increase with time, even block the whole channel and then the flow pattern changes into slug flow gradually. Larger current density, more easily is it to block the channel. It's also shown in the power curves that there exists an evident influence of gravity in the regime of the concentration polarization. The diminution of the power performance of DMFC in microgravity increases with the degree of the concentration polarization.