We report the simultaneous extreme ultraviolet observation of magnetic reconnection inflow and outflow in a flare on 2010 August 18 observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory .
We found that during the rise phase of the flare , some plasma blobs appeared in the sheet structure above the hot loops .
The plasma blobs were ejected bidirectionally along the sheet structure ( outflow ) , at the same time as the threads visible in extreme ultraviolet images moved toward the sheet structure ( inflow ) .
The upward and downward ejection velocities are 220-460 km s ^ { -1 } and 250-280 km s ^ { -1 } , respectively .
The inflow speed changed from 90 km s ^ { -1 } to 12 km s ^ { -1 } in 5 minutes .
By using these velocities , we estimated the nondimensional reconnection rate , which we found to vary during this period from 0.20 to 0.055 .
We also found that the plasma blobs in the sheet structure collided or merged with each other before they were ejected from the sheet structure .
We hypothesize that the sheet structure is the current sheet and that these plasma blobs are plasmoids or magnetic islands , which could be important for understanding the dynamics of the reconnection region .